Beyond 6g...

[TheDS]

Uh, a black hole small enough to be "portable" (million tons?) will evaporate in under a second; probably WELL under. Calculate that as all mass being converted to energy. You'll be as bright as the Sun for a moment.

Of course, ACQUIRING a black hole that's under a couple solar masses will also be a problem.

 

[Space Cadet]

Ok TheDS, if you were to design a black hole powered star ship, what would the minimum size black hole be? Think of a World ship, say a cylinder that rotates for gravity, it would have some matter that it feeds into the black hole at the same rate that the black hole evaporates to convert matter into energy.

The manufacture of black holes might be made easier if gravity was a 4-dimensional or 5-dimensional force at short distances. If you had a series of particle accelerators that make temporary black holes and then quickly merge them into large black holes before they decay, and merge those in turn into still large black holes and so on and so on, increasing the mass or each resultant black hole so that it radiates slower. Above a certain mass you could simply force feed the black hole till it grows larger still until its relatively stable and converts only a small percentage of its mass into energy such that that percentage is equal to the inflow of matter.

 

[atpollard]

If I were designing a 'black hole powered ship', I would find a naturally occuring black hole and 'hollow' out the center for the crew compartment (like a buffered planetoid). If I could manufacture black holes, then resisting the efects of a natural black hole should be a simple matter.

 

[Stei'awtliyrl]

What was the reasoning (if any) for the 6-G limit in the first place, from a setting standpoint. After all, there is a canonical Jump-6 limit which Traveller era scientists are attempting to overcome.

 

[far-trader]

Originally posted by Stei'awtliyrl:
What was the reasoning (if any) for the 6-G limit in the first place...

I suspect it, and the jump limit, had nothing to do specifically with the setting but a lot to do with the small numbered cubes used to play the game

And maybe a need to set a limit (some limit, and 6 seemed natural) to allow the game to fit a certain page count without having huge tables for ship design.

 

[Whipsnade]

Originally posted by Stei'awtliyrl:
What was the reasoning (if any) for the 6-G limit in the first place, from a setting standpoint. After all, there is a canonical Jump-6 limit which Traveller era scientists are attempting to overcome.

Stei'awtliyrl,

The jump distance limit is 36 parsecs actually. It's only when you want to control the jump in question that it drops to six parsecs.

As Dan wisely pointed out, the limit as everything to do with the dice the game used.


Have fun,
Bill

 

[veltyen]

:Context: Relativistic travel universe

Originally by Space Cadet:
What do you think about centering a Traveller campaign based on this technology?

There are a couple of novels set in that type of universe, where extreme speed travel with extensive time dilation is everyday. Orson Scott Card: Ender Universe is one, though it cheats and has faster then light communication. David Brin: Uplift has some aspects of the same (the spacers oath, no expectation of significant temporal continuity for travellers).

This is difficult for a campaign. With a 9 year turn arround to the NEAREST system, but more likely a 30-40 year lag to somewhat more useful systems, means that everytime you visit a world it is COMPLETELY different. Effectively every jaunt is a trip into the complete unknown, even if you are going home.

There doesn't seem to be a lot of change in 10 years while you live through it, but skipping from one to the next would be extremely disjointed.

From a narrative point of view, that travel system would be fine for a colony game (Beowulfs children, Blue Planet) but would be difficult to set "on ship", unless the ship you set it on was in-system in a multi planet colony (such as firefly).

That said I have run a campaign with some aspects of that culture (Faster then light travel, but colonies deliberately minimised communication with each other and were widely dispersed). Thematically you need to look at big picture issues, ones that will still be valid 5, 10 or 100 years in the future or past. Short term issues (piracy, civil wars, money) stop having any meaning. The other theme that can be used is closed circuit, where the action is entirely internal to the craft being travelled on (generation ships lend themselves to this, but fall a little too much into the closed room mystery genre).

 

[TheDS]

Ok TheDS, if you were to design a black hole powered star ship, what would the minimum size black hole be? Think of a World ship, say a cylinder that rotates for gravity, it would have some matter that it feeds into the black hole at the same rate that the black hole evaporates to convert matter into energy.

The manufacture of black holes might be made easier if gravity was a 4-dimensional or 5-dimensional force at short distances. If you had a series of particle accelerators that make temporary black holes and then quickly merge them into large black holes before they decay, and merge those in turn into still large black holes and so on and so on, increasing the mass or each resultant black hole so that it radiates slower. Above a certain mass you could simply force feed the black hole till it grows larger still until its relatively stable and converts only a small percentage of its mass into energy such that that percentage is equal to the inflow of matter.

Sorry I didn't see this sooner.

I don't have the math or figures available to me to give hard figures, so consider this to be back-of-the-envelop, wildass-guess calculations.

IIRC, the minimum mass a star can be to form a black hole is on the order of 10 solar masses, and the resulting hole is around 3 solar masses. No idea how long such a hole would last, but considering the observations necessary to support this, it's probably billions to trillions of years.

In our solar system, we have about 1.01 solar masses of material available. Take a look around you right now. That big rock you're sitting on is an insignificant mote compared to Jupiter, which is a mote compared to the sun. The sun puts out an amount of energy equivalent to the antimatter annihilation of 4 MILLION TONS of mass PER SECOND. Think about that. That's more energy than has existed on the planet in its entire 4.5 billion year lifetime, asteroid impacts and nuclear weapons included.

So, the short answer is: I wouldn't. The numbers boggle the mind, and I'm not even an engineer, who I'm sure would laugh you right out of his office for making such a proposition.

Actually having and feeding a black hole would create loads of radiation. I don't think you'd be allowed within 100 parsecs of an inhabited system, if you could even figure out a way to move it. But I suppose if you have the ability to catch/build one and not kill off the crew, then you can figure out some way to channel the energy in one direction and make a thruster out of it, or warp spacetime in some way. See, that's the other problem here: anything you or I say that makes it possible can be used to justify just about anything.

As to merging black holes into bigger ones, I really can't see a scenario where that's a good idea. Collisions like this tend to make big bada-booms, kinda defeating the purpose, and we're not talking about aggregating soap bubbles, we're talking about aggregating moon-masses or thereabouts. The rate at which you have to feed a black hole to make it gain mass, when it's moon-mass MIGHT be at the rate of X moons per second, but as I said earlier, I don't have the numbers to tell you for sure. Maybe (seriously) you could ask Dr. Hawking; I have no idea if he accepts fan-mail, but it's worth a try.

 

[pendragonman]

Stei'awtliyrl,

The jump distance limit is 36 parsecs actually. It's only when you want to control the jump in question that it drops to six parsecs.

As Dan wisely pointed out, the limit as everything to do with the dice the game used.


Have fun,
Bill

What is the fun of a controlled jump? You only go to where you originally set out for. What fun is there in that? :rofl:

Seriously though. Can anyone think of a more logical limit (from a game mechanics standpoint, not necessarily from a plot line standpoint) than the one that coincides with the type of die used?

As to the acceleration limit, I have seen people house rule higher G's but limited their use to space craft under 100 tons. So fighters could go 9 g but a 100 or greater ton vessel could max out at 6 g. This allowed fighter to intercept faster, and allowed for missiles to intercept at up to 12 g.

We had to use greater amounts of volume for a strengthened internal structure to do it, though.

 

[Icosahedron]

Perhaps accelerations over 6G require all personnel to be strapped into acceleration couches?

 

[fredofmars]

<snip>Seriously though. Can anyone think of a more logical limit (from a game mechanics standpoint, not necessarily from a plot line standpoint) than the one that coincides with the type of die used?<snip>

The rationale I use is that thruster plates (and associated acceleration compensators) only work up to 6G based on the physics used to construct them. Of course the IN and others are researching ways to increase that limit, but haven't come up with anything yet. I also limit thruster plates to about a third of 'c' maximum (they don't provide any additional thrust once you get that fast), with a pretty steep drop off as you get faster. Thus, IMTU you won't get near-c rocks pushed by thruster plates (Aslani in comfy shoes are another matter :devil.

I do allow other systems to be used IMTU, so for example you could have a HEPLAR based ship with whatever acceleration you wanted to design in. I'd even allow mixed ships, so you could have thruster based acceleration compensation of 6G, then add on HEPLAR for additional acceleration (that would be uncompensated beyond the initial 6G).

 

[Butch Clor]

6G and Beyond Question

Friends,

IMTU and over the decades in discussions with other players we have come up with a few rules comments /definations.

One of the original reasons for the 6G limit were the board, game ship to ship combat games. These were played normally in the LBB era without computer or calculator assistiance for vector mechanics. It made the play area workable.

Now on those futher years.

M drives beyond 6 are possible. We use these mostly for Torpedoes (large 2-5dT missles) the progression stays the same,; 3% larger than the previous drive,ie:M-6= 17%, M-7=20%, M-8=23, M-9=26, M-10=29, these can go to M-11=32%. The controlling factor is that compensator technology maxes out at 6G until TL-18. Using this concept a Ship or boat could have a M-7 drive and the crew would take a -1 to all personal stats, per turn., if M-8, -2 to stats. Of course when any personal stat reaches 0 the player in unconscious; with all the ensuing results. Acceleration couches or Battle dress could offset this but only for a max of number of turns equal to the crew members B/Dress skill, or their O-G skill for couch use.
Our most common use were on Fighters and SDB's for an afterburner effect, that way you wouldn't have to be exposed to the stresses that long a time period.


Hope this helps
Butch

 

[Captain Midnight]

Seriously though. Can anyone think of a more logical limit (from a game mechanics standpoint, not necessarily from a plot line standpoint) than the one that coincides with the type of die used?

It only coincides with that number if you assume TTL 15; if you're working at a lower TL, it is a lower number, and depending on your rules, you might be able to get higher at higher TLs (High Guard, for instance, only defines jump capability to TTL 15, but doesn't address what happens beyond that).

There are also different rules in different systems for handling maximum accelerations; MT doesn't allow inertial compensation until TL 10, for example, and GT allows 9G compensation at GTL 13+.

 

[Deliberatus]

thrust is where you find it.

Drives are NOT telepathic. they do not KNOW how much stuff they are pushing.
Slap a BIG drive on a SMALL payload, it goes like hell. You got ther amps, you got the space for teh gear, you got the oomph.

Modern (TL12+) drives use advanced gravitics to lift the entire payload- including you- so there's NO apparent acceleration at all- the gravitic frame of reference is lifting everything inside it evenly. the more you weight, the more you interact with the lifting field. The internal grav better stay on, or you will be WEIGHTLESS- while accelerating at 39 m/s/s!!!

TL11 AND LOWER USE IONIC DRIVES- VERY HOT (HIGH VELOCITY) PLASMA COMING OUT THE BACK, AS A REACTION DRIVE. This creates 'setback' forces- inertia rears it's ugly head. Internal gravity plates COULD be used to offset this effect on cargo and personel- but the hull is still being stressed, you just feel good about it.

The real limit is not physics, or even economics, but is SPACE. A ship with 23% being propulsion system (IMTU, MD8) and 8% as power system, and 8% fuel, is 39% LEGS, before anything else is added. that's ok for a fast scout, but not for a battleship- there's just too darn much stuff dedicated to one aspect of the ship's operational profile.

You REALLY want to build a TL15 MD10 system, you can do it. Darn few missions need it, darn few mission profiles can be executed by it.
But in no kidding war, the fleet turns REAL nasty.

UBETTA U A** that robot hunter killers are all legs; they need no explosives only mass on impact, which kills as bad or worse.

You can launch one of these bad boys from a 50T bay, or a brace of 3 in a deadly dance of robot love from a 100T bay- and there's reloads in the bays... Nasty dreams, what? Dodge, block, and shoot back, serious warmissiles are high Delta V killing machines, and they want to mate with you- at 75Km/S.

Give one of them monsters 6% for sensors and brains and they will run you down and smack into you with a 5 ton MD12 lovepat that will make the owner smile- and at that capacity for delta V, only relativistic mass driver guns and lasers can defend against it- and sand-clouds, which vaporize the brain and sensor pack, turning it into an unguided missile. DODGE MAN DODGE!!! Long ranges let them get up to a running start, which makes them more deadly, but also easier to dodge. House rules, you can figure it out. Trust me, the impact is SO worth it when they connect. It WILL ring their chimes.

 

[shadowcat20]

I suspect faster speeds will not be possable for merchant ships. The crew may be able to stand the stress for a short time but how about the cargo? Tie downs may fail, containers may rupture, and cargo not packed tight or safely may get damaged. There has to be some sort of standard set for cargo pods. Then some cargos just plain can not handle the stress.

Space is also a factor, you loose too much cargo space for the larger drives and fuel. As someone else on this thread also pointed out you would need a high performance stamp on your pilots certificate to be able to run such a ship. Also parts for exotic engines like these could be hard or impossable to find. Everything would have to be custom built and very high prices. Maybe require double refined fuel like aircraft use avgas rather than fuel we use in our cars.

It could be done, but at a high price and much difficulty.

 

[Hemdian]

The controlling factor is that compensator technology maxes out at 6G until TL-18.

Thanks. I'd thought the same thing myself but had yet to get around to working out the numbers.

 

[FreeTrav]

The problem that you're discussing here isn't speed, it's acceleration - and/or jerk. If you're moving at a constant speed, there's actually no more stress on things like tiedowns, bulkheads, crew, et cetera, than there is when the ship isn't moving at all.

(For the physics-fuzzy:
Velocity (speed) is change in position/distance-from-origin per unit time;
acceleration is change in velocity per unit time;
jerk is change in acceleration per unit time.)

(For the mathematically inclined:
Given distance-from-origin S...
... Velocity (v) is dS/dt
... acceleration (a) is dv/dt, or d²S/dt²
... jerk (j) is da/dt, or d²v/dt², or d³S/dt³.)