Star Drives

[Prime_Evil]

I've been working on a setting that using traditional Traveller jump drives, but also permits rapid travel across vast distances using a network of artificial wormholes. Artificial wormholes must be stablilzed by feeding them a constant trickle of exotic matter - failure to do so causes the wormhole to collapse in a matter of hours. Wormholes are very expensive to build and maintain, so they tend to be constructed only in important systems such as sector capitals, major industrial hubs, strategic military bases, and locations of great cultural or religious significance. Systems that contain a wormhole terminus grow wealthy from interstellar trade so there is often fierce competition between rival worlds to establish the first wormhole in a subsector. Because the technology necessary to build wormhole links over interstellar distances is still very young, many systems are still 3-5 jumps away from the nearest wormhole terminus. The result is a situation reminiscent of the age of the railroad barons in the Old West where the megacorporations who build these transportation networks weild immense political power and often engage in dirty tricks to secure exclusive influence over entire subsectors. The Core Worlds are already linked by a dense tangle of wormhole networks, but out in the frontier sectors they are far and few between. Systems located several jumps away from the nearest wormhole are often regarded as backwaters.

This approach is not particularly original and has been influenced by a number of SF works including David Weber's Honor Harrington series, Jack Campbell's Lost Fleet Saga, and Lois McMaster Bujold's Vorkorsigan Saga. My main contribution is to depict a setting where wormhole construction is still an new technology while the jump drive has been around for several centuries. The political implications of such a transformative technology are interesting to say the least - as outlying systems find a wormhole network getting closer, the central government of the setting begins to exert greater control over their affairs. Many frontier systems enjoy the relative independence that travel and communication delays have given them and resent the expectation that they will simply fall into line when the government tells them to jump. The result is similar to the scenario in Firefly where the Alliance government is gradually extending its power across all of the distant human colonies. To make matters worse, trade over the wormhole links tends to be dominated by massive interstellar conglomerates who are often hostile towards local operators such as the independent tramp freighters owned by adventurers....

 

[Condottiere]

That changes history as well, since Empires will fight to control the wormholes, and civilization (assuming it depends on trade and exchange of ideas) will form hubs radiating out from the termini.

 

[Prime_Evil]

That changes history as well, since Empires will fight to control the wormholes, and civilization (assuming it depends on trade and exchange of ideas) will form hubs radiating out from the termini.

All of these points are true, but I've deliberately set things during the period where the wormhole networks are being constructed so that the PCs can be involved in the process. This is a period where the frontier is being 'civilized' (or at least pacified) as a faster form of interstellar travel becomes available. As new hubs are established, trade routes shift and new patterns of military deployment emerge. Lawless systems that once served as classic "hives of scum and villainy" (pirate havens, smuggler outposts, and the like) suddenly find that they are no longer beyond the reach of law enforcement. It's an interesting time to be a free trader....

 

[Tom Kalbfus]

Wormholes can also be used as time machines, an alien-made wormhole might allow travel to Earth's past. If for example a wormhole was 1 billion years old, the time dialation differential between the wormhole ends need only be slight. 1000 years is one millionth of a billion years, this could come about from one end of a wormhole being deeper in a gravitational well than the other, such as for instance being closer to the center of the galaxy for example. As for changing history, that's easily handled, a wormhole could connect two universes.

 

[Prime_Evil]

In my ATU there is evidence of wormhole networks built by extinct alien races who used them for time travel. How they achieved this is a mystery to modern humans as wormholes used for time travel always self-destruct as quantum vacuum fluctuations generate a feedback loop, looping through the throat of the wormhole over and over again. Some scholars believe that these species may have been wiped out because they tampered with their own history. I've hinted that the first alien civilization to achieve sentience (my equivalent of the Ancients from the OTU) is still around in the distant future and will intervene if other civilisations violate causality within *THEIR* historic light cone (since time travel could be used to threaten THEIR existence...). Who the Ancients are and where they are hiding is one of the mysteries of the setting.

From a campaign design perspective, adding artificial wormholes to a setting has the advantage that their locations are fixed and can be placed as the GM desires. I've ruled that the equipment required to maintain a wormhole is massive and is usually placed in space at the edge of the system. I've also ruled that two wormholes cannot be constructed close to each other, so even those lucky systems with two wormholes, ships may need to spend a couple of days cruising between them at sublight speeds. And even if it is possible to move one end of a wormhole through normal space by mounting maneuver drives on the engines that mainain it, you can't move very fast - as you approach a sgnificant fraction of the speed of light the wormhole becomes more and more unstable. And if you ever try and jump to superluminal speeds, the wormhole instantly collapses (releasing all of the matter and energy caught inside it in a tremendous blast).

Based upon the needs of the campaign, artificial wormholes can be as rare or common as the setting demands. I've deliberately made them uncommon so that the normal Traveller rules can be used most of the time, but having them in the background does change the 'feel' of the setting quite a bit. At this point I've dodged the question of whether electromagnetic signals can be transmitted through artificial wormholes, as this would allow FTL communication - but only between the two points linked by the wormhole. Still, with relay stations built near each wormhole terminus it would be possible in theory to gradually construct an interstellar communication network (presumably with automated routing between 'wormhole hops'). Communication delays would be limited to the amount of time required to relay the message between wormholes. Because the next wormhole on the route to the message's ultimate destination might be several light minutes away, these delays would quickly accumulate. Still, such a system would change Traveller almost beyond recognition. If the wormhole networks are like railroads being extended into the Old West, that FTL communication relay stations might be like the telegraph lines that follow in their wake. This approach could work, especially if the amount of bandwidth available through a wormhole is so low that the experience is a bit like viewing a graphics-intensive website on a 56K modem, but its still a large departure from Traveller norms and the implications would need to be considered with care. Scout Service X-Boats would still be used to link outlying systems to the main communication routes, serving a role similar to the Pony Express...

 

[Lord High Munchkin]

That is a communications and transport set-up very much like that postulated in many novels... off of the top of my head, Iain M. Banks' 'The Algebraist'.

I use a very similar concept in my games (there are differences, but basically similar).

 

[Prime_Evil]

It does give the setting a very different feel to the OTU.

The limitations on interstellar travel and communication in the OTU have more to do with game balance than scientific plausibility. Restricting most starships to jump-1 or jump-2 makes it possible to run a sandbox campaign without overwhelming the GM with prep work. Assuming that adventurers can only make one or two jumps per game session, the maximum number of new systems that a GM needs to detail between game sessions is restricted to 4-6 (assuming the normal random distribution of inhabited systems). It also means that a single subsector can keep a party busy for at least a couple of weeks. This isn't a setting where starships travel at the speed of plot and can travel from Naboo to Coruscant in a single jump...

 

[Tom Kalbfus]

With wormholes your limited to the systems with nearby wormholes with each wormhole connecting two systems.

 

[Prime_Evil]

With wormholes your limited to the systems with nearby wormholes with each wormhole connecting two systems.

That's correct. But a single system can have more than one wormhole - provided that they are at least several light minutes apart. The most important systems - from a strategic, economic, and cultural perspective - lie at the junctions between different wormhole networks. These are locations where transshipment between different destinations occurs.

An assumption of the setting is that shipment through the wormhole networks is dominated by massive bulk freighters owned by vast interstellar shipping conglomerates - free traders survive in the margins where it isn't profitable for the big players to operate. Out on the frontier there aren't many trade routes with wormhole links, so freight tends to be transported the old-fashioned way. It simply isn't profitable to send a bulk freighter to every minor outlying colony, so these are places where free traders can survive. Also, a small independent freighter can survive on a profit margin that wouldn't cover the monthly maintenance budget of a corporate bulk freighter.

 

[Tom Kalbfus]

Depends on who built the wormhole. If the wormhole is private property, then yes, but what if the Wormhole was built by the government, an interstellar equivalent to the highway department? The wormhole then is funded by taxpayers, a great many taxpayers will be free traders, and if the government says, "No these wormholes are reserved for corporate fat cats that make big donations to politicians reelection campaigns, your going to have a massive rebellion, and they are going to get voted out of office.

 

[Lord High Munchkin]

Depends on the type of government... there might not be any "voting".

 

[Condottiere]

Some votes are more equal than others.

 

[Tom Kalbfus]

You could have multiple governments, each controlling their own wormhole networks. In fact they could charge tolls instead of taxes, it would be sufficient that they control the wormholes to raise revenue, but they would also want to maximize their revenue, so the question is how? Do they let in only a few big corporations or do they let everyone us them so long as they pay the toll, perhaps charge proportionally to hull tonnage perhaps.

 

[Prime_Evil]

You could have multiple governments, each controlling their own wormhole networks. In fact they could charge tolls instead of taxes, it would be sufficient that they control the wormholes to raise revenue, but they would also want to maximize their revenue, so the question is how? Do they let in only a few big corporations or do they let everyone us them so long as they pay the toll, perhaps charge proportionally to hull tonnage perhaps.

This is similar to what I am doing for my campaign - human civilisation has fragmented into several competing starfaring polities and each maintains one or more wormhole networks. Some of these polities have friendly relations and maintain shared connections between their respective territories, while others do not. In most cases, artificial wormholes are built by megacorporations under license from governments. Due to the immense cost of building a wormhole terminus and the high level of technical expertise involved, planetary governments may finance the initial construction project by issuing bonds or other securities. The other alternative is to finance the project through a public - private partnership and offering the financial institution that covers the construction cost a lease over the completed wormhole and the right to charge tolls. These tolls are indeed always proportional to hull tonnage simply because the negative energy density required to keep the throat of the wormhole open is proportional to the mass of the object passing through it. While a starship is in transit through the wormhole, the total mass / energy of the wormhole increases by the total mass of the ship. Also, the throat of the wormhole must be large enough to prevent tidal forces from ripping starships to shreds as they traverse it - for safety reasons, transits are usually performed under the supervision of the AI that manages local traffic control rather than under the control of human pilots.

To complicate matters, a number of alien species have their own wormhole networks - some of which may be far older and more extensive than that of their human neighbours. There have been a couple of cases where humans have stumbled across alien wormholes inside their territory and hilarity has ensued (see below). There are at least two abandoned wormhole networks built by extinct alien races that extend at least partially into human space.

One of these is occasionally used by other starfaring races, which has led to awkward situations where alien starships have suddenly turned up deep within the territory claimed by human polities. Usually, diplomats and xenologists are scrambled to sort out the resulting mess. In addition, on at least one occasion the Outworld Alliance used this ancient wormhole network to drop a military force behind enemy lines during the closing stages of the Colonial Wars. As you can imagine, mapping out the remaining wormhole links on this network is a high priority for the scout service of every human polity. However this is a risky endeavour as some explorers never return. Automated Survey Drones are often sent down active links, but the quality of the data they return is often inferior to that gathered by a well-trained human crew .

The other abandoned alien wormhole network is extremely ancient and was built by my version of the Ancients. It is estimated that the few surviving wormholes from this network are at least 70-80 million years old, but they all seem to be in perfect working condition. These structures violate many of the rules of wormhole travel as they are known to current science, allowing time travel to occur without collapsing due to quantum inequalities. Signals sent through these wormholes often propagate before they were sent, forming causal loops. At least one wormhole has been discovered that connects to a star system in a neighbouring galaxy at some point in the very distant future - from this vantage point, the fading stars of the milky way are metal-depleted and there are signs of a dozen supernovae that do not exist in our time period. The team of xenologists who travelled through this wormhole and explored the system at the other end vanished under very mysterious circumstances and the scientific data received from them remains classified. It is publicly known that they detected evidence of psionic disturbances of some kind shortly before they vanished. The contents of the final transmissions have been shared with the other polities and all of them agree that further interference with these alien wormholes must not be permitted - whatever information they contained was sufficient to convince even bitter enemies that messing around with the spacetime engineering of the ancients is NOT a good idea...

Finally, my campaign setting also features a wormhole network built by a machine civilisation that maintains polite but distant diplomatic relations with humanity. This robotic civilisation was founded by a rogue human AI during the Diaspora period following the Transhuman Wars and has been gradually expanding rimward of human space. The machine intelligences of this polity maintain a strictly neutral stance in the affairs of other species and appear to be pursuing an isolationist foreign policy. Their intentions appear to be peaceful and they seem happy to trade with humans at locations designated by treaty, but they do not allow sentient organic beings to enter their territory at all. Their wormholes seem to be built on slightly different engineering principles than those constructed by humans, with a cube-like design similar to that proposed by Matt Visser in 1995. The other characteristics of these wormholes appear to be similar to their human equivalents. The machine intelligences also appear to have a warp drive that allows interstellar travel in normal space, but information about this is sketchy as these starships are rarely seen near human space.

 

[Yatima]

Here's the best discussion of FTL alternatives on the Internet:

http://www.projectrho.com/public_html/rocket/fasterlight.php

It includes Landis's Canonical list of all the types of star drive in science fiction, and lots of discussion of how the choices an author/campaign designer makes about whether and how FTL travel and communication work determine the nature of the economy, society and warfare for the setting.

The discussion of Niven and Pournelle's Alderson Drive FTL system for their Mote in God's Eye novel should be required reading for science fiction campaign designers.

 

[Prime_Evil]

Here's the best discussion of FTL alternatives on the Internet:

http://www.projectrho.com/public_html/rocket/fasterlight.php

Yep...that's a good page

I'd also recommend the book "Time Travel and Warp Drives" by Allen Everett and Thomas Roman (University of Chicago Press 2012) - this gives an accessible introduction to the physics of FTL travel by a professor emeritus of physics and a professor of mathematics. It's been recommended by KIp Thorne himself...

 

[Rikki Tikki Traveller]

Depends on who built the wormhole. If the wormhole is private property, then yes, but what if the Wormhole was built by the government, an interstellar equivalent to the highway department? The wormhole then is funded by taxpayers, a great many taxpayers will be free traders, and if the government says, "No these wormholes are reserved for corporate fat cats that make big donations to politicians reelection campaigns, your going to have a massive rebellion, and they are going to get voted out of office.

It could be even more complicated with each end of the wormhole being owned by a different government. You pay a toll to enter AND to exit... There is a consortium of course that built it, but each government gets their taxes...

 

[Tom Kalbfus]

Depends on who built the wormhole. If the wormhole is private property, then yes, but what if the Wormhole was built by the government, an interstellar equivalent to the highway department? The wormhole then is funded by taxpayers, a great many taxpayers will be free traders, and if the government says, "No these wormholes are reserved for corporate fat cats that make big donations to politicians reelection campaigns, your going to have a massive rebellion, and they are going to get voted out of office.

It could be even more complicated with each end of the wormhole being owned by a different government. You pay a toll to enter AND to exit... There is a consortium of course that built it, but each government gets their taxes...

No, I don't think you pay a toll to exit a wormhole. If a person is stuck inside a wormhole because he can't pay the fare to get out, then the wormhole is blocked, this is aside from the point that anything traveling through a wormhole is probably traveling near the speed of light, due to gravity, at mid-transit and there it no stopping it!

 

[Rikki Tikki Traveller]

No, you let him out, then confine his ship until he pays. Can't block the money-river!