Going Pirate

[Straybow]

A slingshot maneuver (as used by NASA to send probes to the outer planets) accelerates with apparent violation of conservation of momentum. The exchange of momentum is moderated by gravity, and the loss of orbital momentum on the planet is too small to measure.

:alpha: Note that I assumed "exchange of momentum with the rest of the universe via distortion of space-time." Since we don't know the mathematics of interaction between a synthetic gravitational effect and the natural gravitational space-time curvature we can't perform momentum exchange calculations. Traveller assumes the limitation is 6 G for gross maneuvering and sufficient spike averaging for effective inertial compensation.
mega:

If you're going to be picky about it , you'd have to apply General Relativity as well (not Special Relativity, which only applies to unaccelerating frames of reference). When you've completed your PhD in Physics let us know and we'll all listen very carefully.

[Corrected per Siggy ]

 

[Straybow]

As for the energy of fusion from D, it's "just the facts" as Friday would say. Traveller already allows fission for TL9 jump engines, and there are rules for larger fission plants and higher tech size reductions.

See the thread I linked to earlier.

:file_22: If they overlooked the effect of concentrated D2 fuel, or for that matter the level of energy possible with proton fusion at higher tech, it is just one more avenue to explore for the rest of us.

 

[mike wightman]

Here's another thought. If we are going to consider high tech fusion (with the benefit of nuclear damper tech to amplify the strong force) then why not allow for He fusion and so on?
Provided it is an exothermic reaction and you get out more energy than you have to put in, even taking into account the energy requirement of the nuclear "damper" that is built into your reactor, then fusion reactions higher up in the sequence (CNO and triple alpha reactions) may be possible.
In which case the fuel formulae from T2300/TNE/T4 may be more accurate.
By the way, Straybow, i agree with you that if D-D fusion is used in fusion reactors then deuterium is all you would carry for your reactor. Maybe that is where the reduced fuel requirements of the above game systems comes from

 

[mike wightman]

If you're going to be picky about it , you'd have to apply Special Relativity as well (not General Relativity, which only applies to unaccelerating frames of reference). When you've completed your PhD in Physics let us know and we'll all listen very carefully.

Actually, if you want to be picky

General Relativity is all about accelerating reference frames (a gravitational field is equivalent to an accelerated frame of reference etc), while Special Relativity is for inertial frames with constant velocity relative to one another.

 

[TheEngineer]

Hi,

well, I guess Relativity not really is a PhD topic anymore

. The math is very simple, just imagination is stressed.
If we would respect simple energy conservation laws, it might be less likely to get into serious Relativity trouble anyway.

"Revising Traveller technology" IMHO would surely include to respect at least these fundamentals for normal space travel.
Especially in order to get away from the constant deadly thread of ultra high velocity starships / spacecraft, effectivly unable to manuever and navigated by weird or drunken pilots

Really, I hate this near-c weapon bug.
But I had to admit playing Traveller a long time, telling my physics-aware but SF-willing players that thrusters are in fact capable of opening micro-gates to another alternate space. Accelerating is motivated by this space. Taking the universe as the sum of all spaces, energy is conserved....yep, perhaps I was drunk.

So IMTU actually I use "energy conservation" for space travel. At least it only has minor effects on normal player activities or gameplay. Space combat still works fine, travel times are a bit delayed.
In fact travel times are quite delayed and microjumps become more common, but I have a more hard-SF feeling now when dealing with in-system travel.

Nevertheless, everytime I think about changing something IMTU to add more "realism" I force myself to the second thought "Is this of any value for gameplay ?". Mostly I come to the conclusion, that it is actually completely unimportant.
Well. at least thinking it over was fun

Best regards,

Mert

 

[Straybow]

Thanks Siggy. I blame lack of sleep for that fumble. It isn't my fault somehow.

About He fusion and higher, the question "why?" comes to mind. The universe is 97% hydrogen. With proton fusion you're going to have cheap, nearly unlimited fuel. The binding energy release for fusion drops significantly as mass increases, so you'd be getting less energy/mass fuel from anything else. Stick with hydrogen.

There could be other reasons for using unconcentrated hydrogen in fusion reactors. Perhaps some trick of physics involved in making fusion work (which we obviously don't know yet) requires the plain H be present in substantial quantities. In fact, I can think of one right now:

For power generation you don't necessarily want to pipe million-degree plasma around, so you might want comparatively large quantities of unheated fuel to dilute the product stream. At the same time you need to return mass into the reactor, and you don't want that mass to be substantially diluted from a fuel standpoint.

In that situation a fuel concentrated to 1% D2 would still work but reduce fuel demand by a factor of 60 (more conservative than my very conservative hand-waving factor "hundreds").

aragraph: Herr Engr, my point about General Relativity is that it deals with the shape of space instead of simplified Lorenz transformations. The math to deal with synthetic distortions of space and their interaction with the "normal" shape of space would likely be PhD material until Gravitics becomes commonplace in late TL10. Unless… you know something we don't…

These things are important for gameplay (though admitted a bit off track in a piracy thread). When fission power requires many orders of magnitude less fuel than fusion something is seriously screwed up!

 

[Anthony]

Originally posted by Straybow:
A slingshot maneuver (as used by NASA to send probes to the outer planets) accelerates with apparent violation of conservation of momentum.

Um...no. A slingshot manuever simply does momentum transfer between the probe and a planet or moon.

 

[Straybow]

No, where do you get that from?

We know it is a transfer of momentum because we firmly believe in conservation. Orbital mechanics initially assumes the planet's energy and momentum is constant (in fact, assumes a non-accelerating frame). The probe changes its vector by the gravity of the planet. Angular momentum of the probe wrt the sun is conserved, resulting in a change in tangential velocity wrt the planet.

In reality the planet gives up a tiny bit of momentum, but that is back-calculated from the probe's change in kinetic energy and not part of the flight mechanics (a higher-order correction to the initial equation can be performed based on the planet's change in momentum at this point).

With Traveller grav tech you can back-calculate the momentum exchanged with the rest of the universe by assuming conservation. There, it's done. To know the distribution of that momentum among nearby objects would be a matter of grav-tech mechanics which are unknown at this time.

 

[TheDS]

Yeah, Anthony. And if you'd read the whole post, you'd've seen that he explained that. So Nya!

Anyway, y'all can blame Sigg for pointing me in this direction. Here is where I came from.

He3 cannot be used because it is radioactive and thus is exceedingly rare!

Based on this idea about damper-catalyzed fusion, I think I am going to decide that Traveller reactors start out as D-D or are CNO cycle, then at TL12 they become P-P, aided by dampers. Naturally, this drastically reduces their fuel efficiency, especially when you go below the probable bottom limits of P-P (about a cubic kilometer), and the smaller you go, the less efficient. Gotta pay for the energy being used to reduce the temperature and pressure requirements of fusion, you know, and the more you lower those limits, the more energy you need.

I will assume that as tech progresses and our bottom limit goes down (as written in the tables) that the reaction gets more efficient at a given volume; basically, the power required for gravitics and strong force and electromagnetics gets less.

The listed bottom limits are going to be the point at which you cannot extract more energy than you are inputting, so no more TL16 backpack fusion reactors for your battledress. Aboce that limit, the diminishing returns will lessen, until you get back to cubic kilometer size, where efficiency will always be maximum (and this maximum may go up too).

 

[BetterThanLife]

How the heck did we get from a discussion of the Practicalities of Piracy to Astro Physics?

 

[Chuck Anumia]

We are going from science fiction to science fact.

 

[Straybow]

The practicalities of piracy depends on the practicality of gas giant fuel scooping (as a means of keeping your pirate ships fueled, and as an important means of providing targets for piracy).

 

[Anthony]

Of course, if there's pirates out there, the practicality of gas giant fuel scooping (which is currently practical for waypoint systems, impractical for destination systems) drops dramatically.

We can, from the canonical interest rate on ships, determine that the odds of a ship being lost for any reason (including, but not limited to, piracy) must not be above 1-2% per year -- or else banks would never offer loans at the rates they do.

 

[graden1]

One house rule I've adopted in my T20 campaign makes piracy a lot more feasible; ship manuever ratings are based on current mass, rather than displacement. For example, a "loaded" far trader masses about 270 metric tons and pulls 2g's, so I give its drives about 540 tons of thrust. Now, a far trader that turns pirate will be running with no cargo, and might reduce its fuel to jump-1 (just enough for a quick getaway), which would give it a 3g manuever rating. Its target vessel will most likely be loaded down with cargo, and unlikely to pull more than 2g's. There is a downside to this; any trader pulling more than 3g's is obviously "running light", and such a merchant ship stopped for inspection would have a hard time explaining why the cargo hold is empty.

This rule also adds a new dimension to the cargo mass/profit equation for smugglers and pirates. A low-volume high-value cargo may be worth running all by itself, even with the rest of the hold empty, if it allows the ship extra speed for running blockades. A corsair vessel "running light" can make 5 or 6g's running a few tons of contraband. With great risks come great rewards....

XO

 

[jatay3]

Try "the Meditterranean" by Fernand Braudel to get a picture of what piracy is like.
Until quite recently(1700's-so)there was seldom any law on the sea except in localized places. People quite openly sailed into port with captured prizes and as long as it was nobody they knew few cared.
Pirates took several forms. There were pirates grande who had whole flotillas behind them and were used as bogeymen by their victims("if you're not good El Draco will get you"). Then there were pirates lite operating out of undeveloped areas, preying on the weakest of the weak and only surviving because they could run into their hills when a vengeful Venetian galley comes looking for them. Much like Indonisian pirates today.
Then their were part-time pirates who were traders or pirates by turn.
Their were some odditys-like one Spaniard who considered it his mission to rescue fleeing refugees off the coast of Algiers. That of course isn't really piracy, but would make an interesting inspiration for a campaign.
Another oddity is the Knights Hospittilers who in between raids maintained one of the best medical facilities in the world, and considered it a sacred duty to minister to the distressed-some of whom of course were distressed because of their raids. These would have considered themselves warriors rather than robbers; but then so would their enemies in Algiers.
In Traveller it would probably it would be very easy to fence prizes beyond the juristiction of the Big Empires(and the more straitlaced of the little ones). Only a few Vargr states would ask all that many questions for instance.
In the Marches their are a number of states with a "sense of humor" but the Zho's and the Imperium-and the Darrians, and the Swordies and the Aslan(both of whom are warlike but have "rules" for how to go about it which would probably not include lawless piracy, though it would countenance formal privatering),would all be looking over their shoulders. The Ardens of course have a "sense of humor"-but they are crawling with spies from the "humorless" states.
Thus the Marches, while a good place for piracy is not without disadvantages. However there is also quite a bit of prey to be had, which is probably less so in Vargr territory.
A Marches pirate would have to be constantly changeing bases to keep ahead of the avenger. Their would be plenty of places to hide but he could not hide forever. His main advantage might simply be that it is impractical to sack every "Port Royal".
A Marches pirate could live on forage, there being enough settled places to simply rob his food. Fuel is more of a problem as a force powerful enough to extort a reasonable sized starport would attract attention. On the other hand he could get fuel from ships. In any case the Marches have plenty of Ports Royal.
A pirate who works in the Marches but is based elsewhere might do well. As long as he is prepared for a long voyage.

 

[jatay3]

The Marches probably have a lot of "ports royal" but only a few "tortugas"

 

[robject]

Originally posted by Xavier Onassis:
One house rule I've adopted in my T20 campaign makes piracy a lot more feasible; ship manuever ratings are based on current mass, rather than displacement. ...

I think this is a great idea.

 

[Chuck Anumia]

Originally posted by jatay3:

A Marches pirate could live on forage, there being enough settled places to simply rob his food. Fuel is more of a problem as a force powerful enough to extort a reasonable sized starport would attract attention. On the other hand he could get fuel from ships. In any case the Marches have plenty of Ports Royal.
A pirate who works in the Marches but is based elsewhere might do well. As long as he is prepared for a long voyage.

The more organized the pirates could become, the more protection and support they could offer each other. Fuel ships could be staged in areas where they are gong to be raiding for faster getaways.

 

[Sephrim]

Combining resources, intel and protection, as well as a market for ill gotten good. Isn't that state formation. Not a bad thing, a Nation is born

 

[Chuck Anumia]

Originally posted by Sephrim:
Combining resources, intel and protection, as well as a market for ill gotten good. Isn't that state formation. Not a bad thing, a Nation is born

Long Live Tortuga!!!