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Revising the science of Traveller

When I see "revised" I think on two dimensions. On one you have the way tech levels are counted. As noted above, more Tech Levels in general allow more "room" for things to develop. Another possibility first brought up by Sophiathegreen in Tech Level Revisions is the notion of sublevels. I agreed, saying,
Every TL needs sublevels, or many more TLs are needed.

Anything introduced in one TL has to wait centuries for another TL before anybody figures out how to make it smaller, stronger, more efficient, etc. That's bull.

If nothing else, improvement of existing tech will happen just because somebody in the thousands of worlds using the tech will look at it and realize "this can be done better like so."

...It would be simple to treat, say, jump drives this way by amending the type: J-1.3 being a third level of miniaturization and efficiency, J-1.C being the 12th level, and so on.

Whether sublevels for any given tech are completely independent or tied to an overall TL sub-index would be milieu specific.
Along this line of thinking I feel there needs to be a general revision of fuel requirements and usage. My first thought on this, years ago, was on efficiency. Why should a TL12 Jump-1 engine have the same fuel requirements as the first commercial Jump-1 engines? Why should the size of the engine stay the same? If I (or my company's research department) can find a way to improve efficiency by 1-2%, or decrease weight/size by 1 dton that represents a huge competitive advantage. I am going to do everything I can to make that happen. My competition is going to do the same.

Not only am I interested in that advantage, so is every starship owner and captain. Large corporations are going to invest in drive research. Most important, the Imperium (or Consulate, or whoever is in charge) is going to be interested, especially when it comes to getting ahead of their competition.

There's a saying: "Once the genie is out of the bottle you can't put the lid back on." In the Ancient and Medieval ages technology was viewed wholistically. A piece of technology, a lock for example, was something that existed as a whole. A locksmith was trained in making locks; he made them the same way his father did, and his father or master before him, etc. Improvement was a cross cultural thing, since locksmithy in China emerged independent of locksmithy in Greece. At some point the cultures met and the products exchanged. Eventually the differences in technique were learned and generally spread both ways. Now locksmiths had two ways to make locks. Change was very slow.

Leonardo da Vinci worked with a German locksmith on improving the design of locks, and he looked at each piece of the lock as a separate entity which could be improved or entirely changed. Not only that, he looked at the way a lock was made and saw that the same technology could be applied to an entirely different problem: the ignition of a gun's powder charge. The first matchlock was the synthesis of arts of gunsmithy and locksmithy.

The German locksmith took both ideas across the Alps, and German craftsmanship began to transform by the power of invention.

Gentlemen, the genie has been out of the bottle for centuries. And unless MM et al are proposing that in the future people will mystically forget how to "invent" the genie isn't going back in. If a certain government fears the inability to control technology and wants to suppress it, that's more power to the competition. The genie just goes somewhere else. Such a short-sighted policy would be a matter of milieu, not of TLs and timelines as a general principle.
 
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Propulsion technology and Traveller

Maybe this has been done before, but I haven't seen it spelled out anywhere else.

I said that I think on two dimensions about revision, and the other dimension is science. Decades ago, as a college freshman, I wondered about the physics of rocket propulsion. Specifically, I wondered how much bang for the buck one could get from fusion power. At the time I didn't know how to go about it other than the broad E=mc² applied to mass differences between fuel and fusion product. As priorities shifted from gaming to degrees and career I left it behind. But that same change of focus eventually gave me an answer.

Given D-D -> He4 reaction releases binding energy as a difference in atomic masses equal to 0.025600318. That is 6.35526920e-3 as a fraction of the initial atomic masses of D. The potential energy from Deuterium fuel is therefore 5.71326e+14 J/kg. But at each step along the way we encounter obstacles.

How efficient is the fusion reaction itself? It doesn't take a large percentage of the fuel to reach the break-even point. But as the reaction progresses He4 concentration reaches a threshold where more fusion diminishes the effective confinement (probability that D nuclei will meet with sufficient energy to initiate fusion). It is impossible to reach 100% efficiency, even in the heart of the most massive star.

Second, how do we transform that energy into propulsion? The TL9 method is the rocket. The first step is to heat the gas by chemical combustion or fusion. Once the gas reaches the speed of sound this is called critical flow. This is the speed at which a pressure change propogates through the fluid, and so pressure alone can't push the fluid any faster. But by releasing the confining pressure on a critical flow stream, individual molecules have a smaller chance of collision and therefore average molecular velocity can increase. The flow accelerates.

A supersonic nozzle works in reverse of a subsonic nozzle: velocity is proportional to the square root of cross section area. The ideal shape is the parabolic bell we see on rocket motors. We might see a 100:1 expansion nozzle for a hydrogen-oxygen rocket motor, which allows an exhaust velocity Ve of Mach 10 (roughly 3 km/s). In a turbojet engine the expansion nozzle is smaller because of the size limitations, but Ve can be augmented by adding fuel into the exhaust stream, called afterburning. A second trick to augmenting Ve is heating the critical flow directly, forcing supercritical velocity in the throat of the nozzle.

Ve bears directly on the amount of thrust produced. We're all familiar with the equation F=ma, but for rocket thrust we use dm/dt, the mass flow rate, and Ve.

F = M·a = dm/dt·Ve

This is of enormous importance, because Ve represents a limit to rocket efficiency. Once the rocket is going faster than Ve the effect of thrust begins to drop off. (As the textbooks say, we leave it to the student as an exercise to investigate this for herself.)
 
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Application of propulsion physics to Traveller

Now let's play Traveller. I'm in a 100 dton Scout accellerating at 2G. It's fusion power, so I can use just a little bit. I can accelerate all day at 2G with only 4 tons of fuel. Oh, really? Let's see how this works. Let's say our supercritical flow rocket with afterheating (can't call it afterburning, we simply inject hot fusion product into the exit stream) has a stupendous Ve of 30 km/s (Mach 100!)

dm/dt·Ve = M·a
dm/dt = M·a/Ve
dm/dt = (100 dtons·5 tons mass/dton)·(2·10m/s²)/(30 km/s)
dm/dt = 333 kilograms/second

:eek: Oops, looks like that 4 dtons (8 tons mass Deuterium) of power plant fuel aren't going to last very long after all: about 24 seconds!!! On the most optimistic, let us suppose that jump fuel is recycled: fusion produces a He4-heavy mix which is cooled through multi-stage turbines and superhot thermocouples for power to jump drive. The waste is stored onboard without baking the ship and its crew (suspend disbelief here). Now we use that for reaction mass, heated in the maneuver drive by the maneuver fuel. We still only have 20 dtons waste + 4 dtons fuel, or 48 tons of D/He4 to exhaust through our rocket nozzle. 144 seconds.

:mad: Rats! Let's look at it the other way 'round and see what ridiculous Ve we need to allow the fuel consumption rate given in Traveller: two days of constant acceleration at an easy 1G (traversing 75 million km: one day accellerating, flip over, one day decellerating to enter orbit).

Ve = M·a / dm/dt
Ve = (100 dtons·5 tons mass/dton)·(2·10m/s²) / (8 tons/(2 days·86400 s/day))
Ve = 216e+6 m/s = 0.72c

Or using the 40 tons of waste from jump drive and the 8 tons waste from the power plant / maneuver drive for reaction mass:

Ve = 0.12c

:( Now we have a slight problem. Our fusion power is limited to 0.006355·Mfuel·c² = ½·Mthrust·Ve² at an absurd 100% fusion efficiency and an absurd 100% efficiency transforming thermal power into thrust:

Ve² = 2·0.006355·c²·8tons/48tons
Ve = 0.046c

Consuming all 24 dtons of fuel to power the maneuver drive (at absurd 100% fusion & thrust efficiences) still only gets us:

Ve² = 2·0.006355·c²
Ve = 0.113c

:cool: Hmmm, Heplar and Gravity plates are looking more necessary at every moment...
 
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Originally posted by Straybow:
Application of propulsion physics to Traveller

[snip]
:cool: Hmmm, Heplar and Gravity plates are looking more necessary at every moment...
well, HEPlaR was still dangerously ascientific...

Gravitic derived thrust seems the right way to go... but o matter what, physics-derived energy requirements based upon our incomplete model(s) of physics are likely to be beond anything that resembles Traveller Technology Combined with Playability in the design sequences...

But more attention needs to be paid to the pregravitic space craft in the core design rules.

And, to be honest, I couldn't care less about time-dialation effects until they exceed the effects of minor jump relativity errors (The jump took 6-8 days in the "Main Universe", and a different ammount of time in the Percieved tie part of the jump, also 6-8 days, but not the exact same time frame...), since any decent relativity effects take such sufficient velocities that interplanetary medium actually begins to have friction effects (mostly radiation ones, IIRC).
 
Since I've never played a game using HEPlaR (is it High Guard, TNE, or ?) I really don't know anything about it. Some have described it as slow, and not based on conventional physics.

If by "incomplete model(s) of physics" you mean E=mc² and the like, and if by "physics-derived energy requirements" you mean equations of motion such as I used, we need that! That is part of what makes the Traveller look 'n' feel. We don't "Go to one quarter impulse" and drive around a star system like a soccer mom hunting for a parking space close to the mall entrance.
 
Hi,

then thinking about drive systems and Traveller I came to the conclusion, that I could live perfectly with any thrusting system, that fits into basic rules of physics, like preservation of energy and momentum (ok, I could live without momentum preservation..).

Question is, why do we need those constantly high g values ?
Just for fast in-system travel and to reach the 100D limit quite quickly, I guess.
If we could scale down at least the 100D limit, we might get along with lower, but more realistic drive performances, without attacking "Traveller" feeling or modifying regular (interstellar) travel times.

And we would be able to get rid of those easy-to-use-c-weapons.

Is this topic untouchable ?

Regards,

Mert
 
Originally posted by Straybow:
Since I've never played a game using HEPlaR (is it High Guard, TNE, or ?) I really don't know anything about it. Some have described it as slow, and not based on conventional physics.

If by "incomplete model(s) of physics" you mean E=mc² and the like, and if by "physics-derived energy requirements" you mean equations of motion such as I used, we need that! That is part of what makes the Traveller look 'n' feel. We don't "Go to one quarter impulse" and drive around a star system like a soccer mom hunting for a parking space close to the mall entrance.
Someone worked out the exhaust velocity of HEPlaR. It was near 0.05 C or more...

So, either, HEPlaR uses some techniques that we can't becuase we have yet to discover the physics principles, or HEPlaR is as "Fantastic" as the gravitic drives it tried to replace.

Since Gravitics as a "Fantasic element" is one of the "Three Big Ones" of Traveller... (Jump Drive is the other major one, the anicients are a minor one, and psionics are a major one.)

Gravitics are a physics hot-button. We know that gravity works. We know that rotating superconductors have apparently had a weight reduction effect in many trials, but it's still not proven how it does it... and it might be we're about to break open gravitics. Or maybe it was just bad anaylsis and methodology...

But without gravitics and gravitic thrust, the CT/MT feel just isn't there. Air/Rafts to orbit and all...

Likewise, Jump Drive doesn't work, but is key to the whole look and feel.

Until The Zhodani were well developed, psionics were not a major part of the setting. And many people consider psionics to be real. Many more don't, but science hasn't had significant serious data collection, either, on psionics.

Meson guns aren't quite so important... and something else should be blamed for the effects...

Physicists haven't yet figured out exactly how many dimentions we exist in. 4 is agreed (x,y,z, time), and between 5 and 26 are common theorizations...

Real World physics are fine, until they interfere with playability. Temporal Relativity is NOT fun to apply, it's calculations and pain-in--the-arse.
 
Greetings to my fellow Travellers.

The original 3 books were the first RPG I really got into, back in '78 or so, and from the start I wrestled with some of the technological elements.

Later works seemed actually to introduce more nits to pick, because they gave more specifics.

Herewith, I offer a few thoughts/opinions.

If a bit of patter about momentum being conserved at the quantum level is good enough for Poul Anderson, then it's good enough for me. Just don't open the way for a "gravitic" perpetual-motion machine.

On the other hand, we already know quite a bit about rocketry; if it's used, it should be fairly realistic.

Unless one introduces some other detail (such as "contragravity" that simply negates the local gee), a ship with a 1-G drive can't take off from Earth! A J-1 ship would be pretty constrained, unless some other source of fuel (brown dwarfs?) could be found between star systems.

Traveller's fusion plants actually strike me now as more "realistic" than they did back when optimistic claims were rampant. The rationale I'd go with today is the potential-well approach. It may allow cleaner reactions (with the right, or "refined," fuel) and produce less waste heat (hence the lack of fins on Traveller ships).

What's "jump fuel" for, anyway? If it's simply fusion fuel, then what of the efficiency of j-drive generators relative to others? That's a can of worms, I suspect. I've always reckoned the drives used fuel in a way directly related to the "jumpspace" phenomenon, so it wasn't relevant to other applications.

The hex-pattern star maps I took to be representations of "jumpspace" relationships. Maybe stars that aren't on the map aren't normally accessible from hyperspace. In any case, a "parsec" on the map isn't necessarily a literal parsec in normal 3-D space. There may be *other* hyperspace planes "above" or "below" the main one (giving access to regions further "up" or "down" in the galactic frame of reference).

To me, the main function of FTL travel in SF is to avoid dealing with massive cultural changes. The basic premises of Traveller, the rationales for the kinds of adventure scenarios we enjoy, depend on a human society very similar to our own.

Introduce the "magic" of nanotechnology, or simply vast supplies of energy, and our pistol-packing trader/mercenary/scouts may become silly.

Whether one recalls Moore's *second* law, invokes cultural conservatism, or assumes that (as so far in the cases of fusion and AI) things turn out to be harder than initially assumed ... one can't have every century in the Traveller universe be as full of change as the one we've just been through in the real world.

Please forgive me if this is all too rambling.
 
I may have said it before, but for me the big thing in Traveller is computer idiocy, and no to little differentiation in non-powered TLs and too much differentiation from tl3-6. The Iron Age is a major leap, after all.
 
Originally posted by Jame]:
I may have said it before, but for me the big thing in Traveller is computer idiocy, and no to little differentiation in non-powered TLs and too much differentiation from tl3-6. The Iron Age is a major leap, after all.
As a historian by initial training I will say that the differences between TL3-6 should be more pronounced.

But, the computer thing has always boiled down IMTU when I ref as a difference mostly in description more than anything. I use more modern terms in descriptions and other semantics.

I have not really had a lot of players trying to program their way out of a tough situation so I can't speak to the programming rules. On a re-read they do seem a bit archaic.

The lack of integration of multitasking ideas into the rules for how many programs the computers can run has always been the basic space time rub for me but it does not take a lot of imagination to get around that.

Finally, if you are referring to the space requirements they are a bit steep. However, I always envision ship computers being big reliable server arrays. If you have never walked into a big production datacenter you might not know what I mean.

All in all, they need to be updated. That is for sure. However, it is amazing to me how much talk it generates over the years.

Play it by ear. Work in some new ideas and descriptions and be done with it.

I imagine interfaces being more like "Minority Reports" and such but that is all descriptive stuff.
 
Well, do we define our TL based on the average tech in use on Earth? No, we base it on the cutting edge of modern tech in use by the military or major corporations.

By that standard the Hittites were working iron four centuries before the conventional date the Iron Age started. It is really silly to try to define the tech of everything in use with a single number, either historically or for a future milieu.

If you want a convenient way to express the standards or limitations of a specific shipyard that's good. But the same planet might have different tech levels associated with other local industries' production, and yet another tech level applicable to what is generally available (by import) for the tiny percentage of people who go around buying high-tech military and starship equipment.

Onboard computers should essentially disappear. We're already at the point where size doesn't matter. The space within a control console is more than sufficient for computer hardware necessary to that console's function.

I can't imagine why equipment wouldn't have integrated electronics. Requiring a program on your main computer to target and fire weapons is like making a car without a steering wheel. A turret would have its own hard-wired control coding with standardized data connectors for maneuvering, sensor, and gunnery input.

Gunnery input would come from a gunnery station, which is what fills that ton of space that has to be set aside. You pay for that (and whatever software it uses) with the turret. The only thing you'd need an external program for would be slaving fire control to the pilot's station.

For engines, the only external programming would be automation-related, not basic operations.
 
Originally posted by Straybow:
Well, do we define our TL based on the average tech in use on Earth? No, we base it on the cutting edge of modern tech in use by the military or major corporations.

By that standard the Hittites were working iron four centuries before the conventional date the Iron Age started. It is really silly to try to define the tech of everything in use with a single number, either historically or for a future milieu.

If you want a convenient way to express the standards or limitations of a specific shipyard that's good. But the same planet might have different tech levels associated with other local industries' production, and yet another tech level applicable to what is generally available (by import) for the tiny percentage of people who go around buying high-tech military and starship equipment.

Onboard computers should essentially disappear. We're already at the point where size doesn't matter. The space within a control console is more than sufficient for computer hardware necessary to that console's function.

I can't imagine why equipment wouldn't have integrated electronics. Requiring a program on your main computer to target and fire weapons is like making a car without a steering wheel. A turret would have its own hard-wired control coding with standardized data connectors for maneuvering, sensor, and gunnery input.

....

For engines, the only external programming would be automation-related, not basic operations.
Ok, I get where you are coming from in relation to integrated systems independent of some central computer.

However, assuming for some reason a central computer system is needed for something, then I would expect that the system could be a more server based type hardware configuration.

Even today, a large server array takes up space, cooling and has a large footprint.
 
What about having a technology tree as an addition for the common TL design?
Certain cultures might develop very diffrently. Some might have a complex understanding of metallurgy, being able to craft alloys like we in the 1950s, but still live without electricity. Quite the opposite ist thinkable, too. What about a culture on a world with only few heavy elements. Or no iron. They would never develop steel, hence having problems with development in our understanding. Without heavy elements like our uranium, radium etc. they might never proof radioactivity like Curie did, but maybe they understand atoms by looking closer into electricity.

UL
 
ACK, I agree that servers can take up much space. The mention of Moore's second law is that programs tend to expand to consume all available memory and storage. Now we have many more users and client processes per user than 20-30 years ago, but the trend is still diminishing physical space requirements per user.

The server sprawl you refer to handles the needs of large corporations with hundreds or thousands of users. Even the largest 20th/21st cen. military ships with several thousand crew don't have an equivalent number of client processes dependent on common resources.

With computers we are dealing with Moore's laws, but we're also dealing with another law: any sufficiently advanced technology is indistinguishable from magic. (I think Clarke is the proper attribution.) The way people access and use information is becoming near magical. This is something we can allow in Traveller without changing it into the Jetsons.
 
Hi !

Originally posted by Straybow:
ACK, I agree that servers can take up much space. The mention of Moore's second law is that programs tend to expand to consume all available memory and storage. Now we have many more users and client processes per user than 20-30 years ago, but the trend is still diminishing physical space requirements per user.

The server sprawl you refer to handles the needs of large corporations with hundreds or thousands of users. Even the largest 20th/21st cen. military ships with several thousand crew don't have an equivalent number of client processes dependent on common resources.

With computers we are dealing with Moore's laws, but we're also dealing with another law: any sufficiently advanced technology is indistinguishable from magic. (I think Clarke is the proper attribution.) The way people access and use information is becoming near magical. This is something we can allow in Traveller without changing it into the Jetsons.
I guess people's way to access and use information is limited by the people themself.
Just today only a minority is able to understand and fully control technical devices.
Guess human beings are going to reach their limits soon
, preventing them from do magic.
This could be a reason why even in the far future the computer need a lot of "interface" space in order to be able to pass this information somehow to these human beings.
So, I have to agree, that processing and memory devices (they merge anyway) will become really - maybe neglegtible - small. What still will take space are peripherical systems for interfaces, interface connectors, commo, power, environmental controls, backup wiring, maintainance access, physical protection etc.


Besides:
One good example for the evolution of client-server systems might be the human being.
Though there are a few thousend/million independent processes running in our body, it seemed to be useful to put control together.
And the relative brain size and power requirements are quite high....

Best regards,

Mert

OP: CAPTAIN ! I HAVE LOST THE MAIN COMPUTER !
Somewhere in the lounge....
CAP: Oh no !
STOP all cleaning bots !
STOP ventilation systems !
Activate main computer on-board beep !
 
As for the computer interface, we already have a big one assigned. It is called the "bridge".
I assume all IT functions are distributed with the systems they regulate. The Bridge area has the information "backbone" and servers as an insignificant part of the dtons mandated. Including triple redundancy. Since the main function of computers in play is to enhance the targeting DM I just treat it as a sensor array.

Jump drive is not fantasy anymore. Difficult, yes, but it is now a maybe. Google on Alcubierre or go here and Here

Maneuver drive... any reaction drive will require rule changes. Except HEpLar, which was a fantasy drive. The Dean drive from the 1960s was probably the inspiration for the "maneuver drive", but it was likely a fraud. In the 1970s G. Harry Stein wrote about a theory called "Davis mechanics" which extended Newtons laws beyond the second derivative and got some interesting results. Has never been proven, though.

Right now the most promising work is by Dr J.F. Woodward on Mach's Principle. It is controversial but mathematically sound.

Gravitics. Robert Forward has discussed this and it is theoretically possible, just as small numbers of electrons can produce disporportionate electromagnetic fields. Conservation of energy still applies, though. So if you are using a constant power supply to accelerate you at 10 m/s (1 G) by the time you double your speed the same power will only accellerate you at 2.5 m/s.


But contragravity strong enough to lift an air raft need only be the negative of 4 tons. Big enough to lift a Scout at 2 G, -200 tons. But the deckplates in that scout produce the same field as tens of thousands of tons of matter.
 
I actually like the way that T20 uses computers - i.e. fiber optic and etc. T5 can use that, can't it?
 
Originally posted by Sigg Oddra:
I liked the computer rules in T4, especially as presented in Central Supply Catalogue.
What were they like?

Never got T4 but the CSC sounds like such a cool book.
 
I'll try to explain, using some quotes from CSC.
To keep things on a manageable scale a problem(program?) that requires the best parallel processing computer at TL7 is given a rating of 1. PCs at TL7 are given a rating of 0. The max rating of a computer system is TL-7. A computer dedicated to a task is given a +1 rating bonus and linking 10 computers gives them a +1 bonus.
If the computer rating is equal to the program difficulty it takes 10 seconds to process. For each rating above or below the program difficulty the time taken is divided or multiplied by 10.
A typical real time language translation program has a difficulty of 3, target or evade ship combat programs 3, global weather forcast 8.
Computer mass and cost vary from TL to TL, but masses start at fractions of a kg for R0 machines to several hundred kg for the high rating machines.
Hope this helps.
 
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