Warp efficiency to jump number

[Drakon]

been doing some comparison between stutterwarp and jump drive gaming rules, and think I am confused.

Assuming jump number is = parsec per 7 day week, and 1 parsec = 3.26 lt yrs. Seff is in units of Lt yrs per day. I get the following stuff.

Jump Seff
1 0.4657
2 0.9314
3 1.3971
4 1.8628
5 2.3285
6 2.7943

The problem comes when looking at the ship specs
The first one in the book, the Anjou cargo ship has a Seff of 2.386 (unloaded). They range from 2.076 (Trilon SSV-21) to 4.068 (Fast Missile Carrier) This is excess of Jump 6.

Or did I screw up the math?

 

[mike wightman]

The maths looks correct

, just remember to take into account stutterwarp range. I think what may be getting to you is the fact that a J6 can travel up to 19.56 light years in 7 days, but still takes 7 days to travel 1mm, if that is the distance the navigator programs. Jump ships do not cover smaller distances faster.

A stutterwarp ship with a warp efficiency of 4.81 (an unloaded Kennedy) will travel 7.7 light years in 1 day, 14.4 hours but then must discharge the stutterwarp for 40 hours. It would take 7.4 days in total to travel the J6 distance, longer if you take into account the few hours spent in each discharge system maneuvering at sublight speeds.

Did any of that make any sense or help in any way?

 

[GJD]

plus j-drive can travel 'line of sight', and SW equipped ships have to hop between gravity wells, potentially making huge detours en route to their destination.

The two drive systems are fundamentally differnt, with advantages and disadvantages inherent to both designs.

G

 

[rfmcdpei]

The two drive systems are fundamentally differnt, with advantages and disadvantages inherent to both designs.

Exactly. For starters, it's possible to use jump drive to make hops to points deep in interstellar space far from any significant mass, whereas stutterwarp ships have to find a mass to break at. If 2300AD didn't have stutterwarp but instead had jump-2, for instance, all that it would have taken to reach the 61 Cygni Cluster would have been a refueling station in interstellar space; you wouldn't have to look for a brown dwarf or Eber stutterwarp.

 

[Drakon]

Thanks a lot for the replies. That has been very helpful.

This and my earlier thread about number crunching elsewhere are the beginnings of my attempt to come up with the game mechanics for an alternative FTL drive for Traveller. Perhaps its just aesthics about the technobabble explaination, but in light of recent theoretical advances in General Relativity, (Alqubierre's paper and the ensuing debate) Traveller's Jump drive no longer sounds plausable to me.

But coming up with a radically different drive system for the game, might render other parts even more unrealistic. Sorry, I am one of those guys who, when a science fiction writer does something that contradicts known science, or sounds highly implausable to me, it spoils it.

The game mechanics have to be balanced, regardless of the explaination. I started looking at the stutterwarp from 2300 rules, and am investigating the FTL drive rules for various different games, consentrating on the many versions of Traveller. I have the technobabble explaination for how the drive works, in my head. The trick is to translate that into workable game rules which will not disrupt the the game too much.

Discharging the energy in the (stutter) warp bubble via bleeding to a gravity well is intriguing. Not sure how realistic it would be however, since most gravity wells are really very slight curvatures of the space time manifold. (this side of black holes, neutron stars and such)

Oh well, what can I say. Sanity is boring anyway.

 

[mike wightman]

This and my earlier thread about number crunching elsewhere are the beginnings of my attempt to come up with the game mechanics for an alternative FTL drive for Traveller

That sounds like an interesting project.

The game mechanics have to be balanced, regardless of the explaination.

Too true. Have you decided to keep the CT -one jump takes one week regardless of distance- or to adopt a stutterwarp type -lightyears per day speed- approach?
I've definately read somewhere that the TNE designers almost changed the Traveller universe over to the stutterwarp.

I have the technobabble explaination for how the drive works, in my head.

I'm sure I am not the only one who would like you to share it. Go on, post it

The trick is to translate that into workable game rules which will not disrupt the the game too much.

Once again post it. Then ask for feedback to refine the game rules.

 

[BMonnery]

Originally posted by Drakon:
Thanks a lot for the replies. That has been very helpful.

This and my earlier thread about number crunching elsewhere are the beginnings of my attempt to come up with the game mechanics for an alternative FTL drive for Traveller. Perhaps its just aesthics about the technobabble explaination, but in light of recent theoretical advances in General Relativity, (Alqubierre's paper and the ensuing debate) Traveller's Jump drive no longer sounds plausable to me.

But coming up with a radically different drive system for the game, might render other parts even more unrealistic. Sorry, I am one of those guys who, when a science fiction writer does something that contradicts known science, or sounds highly implausable to me, it spoils it.

The game mechanics have to be balanced, regardless of the explaination. I started looking at the stutterwarp from 2300 rules, and am investigating the FTL drive rules for various different games, consentrating on the many versions of Traveller. I have the technobabble explaination for how the drive works, in my head. The trick is to translate that into workable game rules which will not disrupt the the game too much.

Discharging the energy in the (stutter) warp bubble via bleeding to a gravity well is intriguing. Not sure how realistic it would be however, since most gravity wells are really very slight curvatures of the space time manifold. (this side of black holes, neutron stars and such)

Oh well, what can I say. Sanity is boring anyway.

Theres a very convincing argument for the drive coil being doped with Tantalum-180m, the metastable form. The decay matches exactly the known effects. The one great unknown is why gravity well discharging works, and why the limit is 7.7ly.

Try groups.yahoo.com/group/2300noncanon we discussed it there about a month back.

Bryn

 

[Drakon]

Originally posted by Sigg Oddra:
Too true. Have you decided to keep the CT -one jump takes one week regardless of distance- or to adopt a stutterwarp type -lightyears per day speed- approach?
I've definately read somewhere that the TNE designers almost changed the Traveller universe over to the stutterwarp.

I am partial to the lightyears per day approach. But speed and range would scale with tech level. I see a need for keeping star travel "slow" and outside of any other forms of communication speed, to preserve the flavor of the setting.

I'm sure I am not the only one who would like you to share it. Go on, post it

Okay, here goes. Bear with me a bit, part of this still needs some work.

In order to travel at the speed of light, one has to create a bubble in space time that separates the ship from the rest of space. You induce a curvature at the leading and trailing edges of the bubble, such that the front of the bubble is compacting space-time, while the trailing edge expands. If you have Alcubierre's paper, there is a figure at the back that shows what I am talking about.

(And if you don't go here: http://xxx.lanl.gov/PS_cache/gr-qc/pdf/0009/0009013.pdf )

This requires the generation of an exotic energy band around the middle of the bubble, at the transistion between the leading and trailing edge.

This energy band, or ring, is generated by the warp drive itself, using a method akin to constructive interference in RF. Essentially the drive generates two sets of frequencies (although gravitationally, instead of electromagnetically) that 'beat' in such a way as to create the equivalent of this exotic energy's effect on the external space-time manifold.

[Grasers, or gravitational equivalent of lasers are not that far off. The problem with construction is the waste energy produced. By the time you get noticable gravity waves from one, you have put so much power in the thing burns up. I have another paper on the subject from the LANL archives, ( http://xxx.lanl.gov/abs/physics/9802037 ) that gives 3 methods of consturction. However at present, the waste energy problem is severe.]

Inside the bubble, the ship is not moving. The bubble itself however can travel at FTl velocities, depending on how fast the space-time can respond to this "flexing" and exact nature of the manifold and its properties. We know it responds to mass and energy, the trick is to find the right distribution to flex it in such a manner to 1) form the bubble, and 2) cause the leading and trailing edges to compress/expand as desired.

(Actually, it requires a series of concentric bubbles, to reduce energy demands to reasonable level. But for our purposes, we can short hand this to just one bubble. The intermediate bubble walls between the inner most and outer most are not important in game terms, except that the gravitational shear is pretty extreme, and deadly.)

The drive itself is an energy conversion system and must be powered from something else. I am thiinking fusion, for all the obvious reasons. The drive won't have its own power plant, however, it will require a LOT of power, well in excess of any hotel loads the ship could possibly utilize.

In game terms, I am thinking that fuel and warp convserion efficiency would go up as Tech level increases. Meaning that speed and range would go up as well. Also, volume and mass of the drive components would go down, as TL goes up.

Ships would have to be fully enclosed in the bubble(s), as any extranious bits would be spagettified upon contact with the bubble walls (except at the transition zone between the leading and trailing edge, which we stuff with exotic energy).

How to steer the bubble might be problematic, and you might be stuck with travelling along geodesics, at least until higher tech levels, and even then, turning is going to be a bit slow.

Misjumps, I have not figured out a way to do, as the bubble is dependent on the transmitted energy. If its going someplace you don't want it to go, pull the plug.

Another paper ( http://xxx.lanl.gov/abs/gr-qc/9907019 ) tells us that one can see through the extreme curvature created by the leading edge of the bubble, and what it would look like.

Anyway, that is the short version. Now to translate this into game mechanics.

 

[Drakon]

Originally posted by BMonnery:
Theres a very convincing argument for the drive coil being doped with Tantalum-180m, the metastable form. The decay matches exactly the known effects. The one great unknown is why gravity well discharging works, and why the limit is 7.7ly.

Try groups.yahoo.com/group/2300noncanon we discussed it there about a month back.

Bryn

Looked at the posts, maybe I am just tired, but it sounds like an economics thing, there is only so much of this stuff on earth. But, there may be plenty of the stuff in the asteroids, or other ring structures right here in our very own solar system. Once you are off this rock, Bob's your uncle.

Anyway, thanks for the information. It sounds like interesting stuff. Correct me if I am wrong, but isn't tantalum a super nova product, rather than produced through the fusion processes inside a star?

 

[aramis]

Alcubierre's paper is, well, only one plausible solution to FTL. Traveller's Jump drive is a littlee more far fetched, due to the fixed duration parabola...

However, since current string-theory models (rapidly becoming more plausible) and other quantum/subquantum theories require at least 5 dimensions (X, Y, Z, Time, and ???), rather than our 4 concrete ones (X, Y, Z, time). Many require at least 7. Assuming time as a constant, jumpspace *in some form* could be the other 3.... or more.

And, if in fact, we do live in a universe of many more dimensions, we get the possibility for many different planes (defining a plane as a set of dimensions which can support objects with sufficient dimensions to match out primary 4 and any others essential to quantum and larger scale physics to operate...).

For gaming purposes, it is probably best if they all share the same time dimension.... for the planes of existance, in order for us mere mortals, at least, to be able to reach them and percieve them. Mechanically, we're 4 dimensions on this plane, maybe more *WE* can't percieve directly. (I like to think that gravity incline is three more dimensions.)

Now, the coordinated quantum tunnelling of 2300 ships is NOT related to Alcubierre's ComEx warp drive, despite gross superficial simmilarities (to wit, a flicker rate, being N-Space FTL drives, and being energy sinks beyond non-ZPE power source feasability under current models of physics).

2300 is "At the pulse, the whole construct leaps X meters in direction Y", while Alcubierre's drive literally distorts the fabric of 4 dimensional N-space to anchor one end, "stretch" the ship forward, anchor the traveling end and unachor the source end, then compress back to shape.

For game purposes, alcuberre's drive COULD explain the game mechanics almost as well (aside from the discharge requirement... which neither model actually resolves...), but 2300 has a clearly defined source cause in canon.

 

[Drakon]

Well, the problem I have with this moving through higher dimensional manifolds, is that first off, there is no indication (to date) that these other dimensions are accessible. 2) That these accesible dimensions offer a short cut, instead of a long cut. And 3) that these alternate dimensions have properties similar enough to the 4 we know to make them usable in the first place.

Yes, Kaluza and Klein showed that General Relativity and electromagnetism could be combined in 5 dimensions, then immediately ran into problems with just what the 5th dimension was, (besides a singing group) and how to account for the apparent 4 dimensional nature of the physical world. Compaction, projection and a host of other possibilities have been proposed, but as of yet, none appear to be the right answer.

[Who was it that showed that in 11 dimensions, the Yang Mills equations, that govern the strong and weak nuclear force, also fall out naturally, just like GR and EM in 5?]

Strings are appealing from a mathematical perspective, but it is still very unclear just what those strings and loops are, or what that other dimensional wiggling really mean, outside the math.

Yeah I know it ain't canon. But if the canon did not bug me, I would not be trying to work out an alternative.

 

[BMonnery]

Originally posted by Drakon:
</font><blockquote>quote:</font><hr />Originally posted by BMonnery:
Theres a very convincing argument for the drive coil being doped with Tantalum-180m, the metastable form. The decay matches exactly the known effects. The one great unknown is why gravity well discharging works, and why the limit is 7.7ly.

Try groups.yahoo.com/group/2300noncanon we discussed it there about a month back.

Bryn

Looked at the posts, maybe I am just tired, but it sounds like an economics thing, there is only so much of this stuff on earth. But, there may be plenty of the stuff in the asteroids, or other ring structures right here in our very own solar system. Once you are off this rock, Bob's your uncle.

Anyway, thanks for the information. It sounds like interesting stuff. Correct me if I am wrong, but isn't tantalum a super nova product, rather than produced through the fusion processes inside a star? </font>[/QUOTE]Well ISTR its the rarest naturally occuring element in the universe, and Ta-180 is 1 part in 8400 of the native element. The ammount on Earth is horribly limited. On the order of a 100,000 tons of the element, let alone the isotope. Its rare enough that people onlist are consider transmutation of the elements as a possible source.

Find it offworld is possible, mainly on tectonically active planets, but in the belt? Never I suspect.

Bryn

 

[BMonnery]

Originally posted by Drakon:
Well, the problem I have with this moving through higher dimensional manifolds, is that first off, there is no indication (to date) that these other dimensions are accessible. 2) That these accesible dimensions offer a short cut, instead of a long cut. And 3) that these alternate dimensions have properties similar enough to the 4 we know to make them usable in the first place.

Yes, Kaluza and Klein showed that General Relativity and electromagnetism could be combined in 5 dimensions, then immediately ran into problems with just what the 5th dimension was, (besides a singing group) and how to account for the apparent 4 dimensional nature of the physical world. Compaction, projection and a host of other possibilities have been proposed, but as of yet, none appear to be the right answer.

[Who was it that showed that in 11 dimensions, the Yang Mills equations, that govern the strong and weak nuclear force, also fall out naturally, just like GR and EM in 5?]

Strings are appealing from a mathematical perspective, but it is still very unclear just what those strings and loops are, or what that other dimensional wiggling really mean, outside the math.

Yeah I know it ain't canon. But if the canon did not bug me, I would not be trying to work out an alternative.

10 dimensions, nos 10 and 11 turned out to be the same dimension.

Bryn

 

[Drakon]

I will bow to your obviously superior knowledge of string theory. I have not followed it for a while. Last I heard 4 gets you GR, 5 Gets you GR + EM, and 11 gets you GR + EM + Yang Mills.

Would love to hear more. Personally, its sounds a bit messy. I know that is not scientific or anything, and it will be interesting to see if string theory sorts out to anything except nice math.

 

[Drakon]

Originally posted by BMonnery:
Well ISTR its the rarest naturally occuring element in the universe, and Ta-180 is 1 part in 8400 of the native element. The ammount on Earth is horribly limited. On the order of a 100,000 tons of the element, let alone the isotope. Its rare enough that people onlist are consider transmutation of the elements as a possible source.

Find it offworld is possible, mainly on tectonically active planets, but in the belt? Never I suspect.

Bryn

Not so sure. Depending on its mass, and how it is produced, there might be tons of the stuff settled around the core of a planet. My understanding is that asteroids are pretty much undifferentiated 'star stuff', leftovers from the formation of the planets. So it would not settle into a core, but just hang around in the rocks.

I am reminded that an initial survey of the asteroid Eros indicates approximately 13 Trillion dollars worth of gold, platnium, and other heavy metals at todays market prices. (Obviously dumping that much metal on the market would cause prices to plummet, and we'd all be playing our game with gold miniatures.

 

[mike wightman]

Drakon, thanks for posting your thoughts.

I am thiinking fusion, for all the obvious reasons.

Which version, the T2300/TNE/T4 with low fuel requirements or the CT etc model?
If you are willing to re-write the FTL rules then how about the power generation rules as well? There is an interesting article at the JTAS web site at the moment about introducing antimatter powerplants at lower TLs, follow this link if you have a subscription.

 

[Pompe]

Tantalum, being heavier than iron, is produced in supernovae, yes. There is rather good reason to assume there would be more of it available in young, high-metalicity systems.

However, I'm slightly confused about the "very convincing argument" BMonnery mentions. Who made it and who was convinced? I searched the list indicated, but it didn't seem as there was an overwhelming agreement of how very convincing it was taken to be.

To me, in all honesty, it seems more as a rather contrived attempt to explain something which essentially will end up being a matter of taste in the end, notably the old drives-empires-powers debate which canon didn't supply enough information on for people to ever being able to agree on the interpretation of. This results in a situation where the most miniscule of published data in products with somewhat contradictory and limited information is taken, after some selective filtering, as evidence capable of extension into some sort of universal laws.

I do not think this is very useful, for two reasons.

One: The information is so limited and so dubious it can't be used in this way. Not only would it be hard in the Real World, but furthermore, this is a _game_. A very good one, but one with the limitations of its creation. Sometimes I get the feeling that people actually spend more time reverse-engineering the population density of the CAR than actually playing the game or creating good backgrounds.

Two: It encourages a sort of canon-debates the 2300ad-community really do not need, debates with no correct answer but with a fair deal of people who think they have one. I've almost never seen such people being able to convince each other or even influence each other. They just want to tell their side.

What I'm saying in this very rambling way is that I think you should do what you think is good, interesting and fun and take the input you receive from that perspective. Multidimensional FTL? Sure, it sounds great to me. Different FTL system and Warp 2? I'd love to hear more. It's a game, bend it the way you want to, and it might be a better game, and many of us likely would love to read your ideas.

 

[Drakon]

Originally posted by Sigg Oddra:
Which version, the T2300/TNE/T4 with low fuel requirements or the CT etc model?
If you are willing to re-write the FTL rules then how about the power generation rules as well? There is an interesting article at the JTAS web site at the moment about introducing antimatter powerplants at lower TLs, follow this link if you have a subscription.

Not a subscriber yet, will look into it. And have not worked out just what the fuel requirements are going to be. You are right, the power generation rules will have to be looked at.

Antimatter makes me nervous. It is extremely dangerous, and seems prone to catastrophic failure should the magnetic containment fail. Also there is the problem of fuel availablity, as there ain't large amounts of antimatter anywhere in the visible universe. Granted, it can be manufactured, but it is economically inefficient. It takes more energy to manufacture than one then gets back out.

Hydrogen gas has an explosion problem, but this is nothing compared to antimatter. While using water would be only produce 1/6 the power of liquid hydrogen, it appears to be a far safer fuel. The question is will it be enough power.

What do you think?

 

[mike wightman]

I agree that antimatter is dangerous, but it may be the only way to ganerate the amount of energy required for your new FTL drive. If you want to stick with fusion no probs. You don't have to worry about hydrogen explosions unless it's mixed with oxygen. Isn't He3 a better fusion fuel?

Of course if you want realy exotic power generation then there's always vacuum energy or even contained miniature black holesboth of which have been seriously suggested as future sources of energy.

Personally I think I would stick to fusion with the possibility of antimatter catalysed fusion reactors or even full on annihilation to power the FTL drive.

 

[Drakon]

Earlier, I did some number crunching on the Jump drives. 5 tons of liquid H comes yields 32 Terawatts of energy, (assuming 100% efficiency). That is a lot of juice, and while any FTL drive is going to require a lot of juice, well, 32 Terawatts is a lot of juice?

He3 would be better, but its harder to find. Hydrogen is plentiful, easily found in a variety of compounds, such as water, methane, irritating people, small pets, garbage

One of my eventual goals is to make as independent a space craft as possible, able to refuel out in the boonies.

I need to work out the rules for the drive first. The various different power plants can wait till later. Earlier I mentioned a paper by Chris Van Dem Brock on how to reduce the energy requirements for a warp drive, by using multiple concentric bubbles. So adjusting the power requirements down does not look that unrealistic.

BTW, we make antimatter where I work. Well positrons (anti-electrons) at least. But they never let me take any home.