Wormholes Hypothetical traversable wormholes may be possible according to solutions for the equations describing general relativity within the real universe. This is if they can be stabilised through negative-energy density exotic matter (Casimir effect constraints and all that). There are even solutions in which natural wormholes can exist and have done since the early universe, being held open by negative mass cosmic strings. In Phoenix we use Inter-spatial Resonance (ISR) as a base mechanic. While not Newtonian in terms of absolute location, it does define all parts of the universe as having a definite resonance. This resonance is not well understood, at least not by anyone other than a few boffins deep in research labs and the occasional exotic alien species who are even more inscrutable. Most bandy the word subspace and shrug. There are two things that are commonly known by star captains, this is that there are epiphenomenon called subspace drift and subspace oscillation.

The former is believed to be related to the expansion of the universe – it seems that the decoupling of energy and mass in the early universe may be just one decoupling of exotic states. The decoupling of space and subspace (all those little dimensions curled up on themselves) meant that given a period of time the constants used to determine jump parameters will change and in unpredictable ways. Professors of esoteric subjects say it is due to cosmic strings and point apologetically at superclusters and the general clumpiness of the universe. They may even dumb it down and say it is not unlike the ripples in sand left behind by the tide. The changes to the constants are analogous to the seawater in contact with the seabed moving over these ripples but also reforming them. Then again they will say anything to ensure their tenure.

The phenomena of subspace oscillation is however a much more extreme version of subspace drift, changing the localised resonance of a region of space by huge amounts. There is some support for these natural wormholes to be from the dawn of time for two good reasons – first, they do not have a shell of exotic matter associated with their openings and secondly there is evidence for them also exhibiting subspace drift. There are rumours (of closely guarded research by certain affiliations) that point towards wormholes naturally changing which systems they connect to.

There are some indications that cosmic strings with 'loose ends' may be responsible for the vast majority of natural wormholes. This would explain why one end of the wormhole is constrained within a region of space though the other end appears to move between systems. It is of course more complicated than that and it may well be proved that in fact it is one of the higher dimension knots described in m-theory that accounts for the localised changes in resonance. Suffice to say, most wormholes have one end that changes its resonance. Each resonance point matches that of another region of space, resulting in the wormhole leading to a new region of space. The two ends are therefore referred to as origin and end-point. The end-point being the side of the wormhole that 'leaps around the universe'.

As natural wormholes are linked to ISR to some degree, it explains why wormholes appear to have a limit on the distance they can span. This is somewhere in the region of a few hundred light years. It is almost certainly a function of the upper limit of the negative-mass cosmic strings generated by the Big Bang.

Of Wormhole Anchors
While natural wormholes are an accepted part of the Phoenix universe, there are those that have found it horribly inconvenient that they tend to undergo subspace oscillation, connecting with multiple locations. Efforts have therefore been made to anchor a wormhole between two regions of space. This would not have been possible without the discovery of gravitron. Gravitron is a peculiar mineral that under normal circumstances is nothing more than dull grey rock. If however it is subjected to certain fields it will induce a negative gravity field. There are even rumours of a world where both gravitron and these fields exist simultaneously – resulting in large floating islands.
While gravitron has positive mass, its ability to generate a negative gravity field can be used to approximate to negative-energy when cleverly applied to a natural wormhole. When done so in sufficient amounts it stops the wormhole cycling. There are two leading theories on this – the first is that it absorbs energy from the wormhole, preventing this from leading to instabilities that eventually cause it to jump its resonance cycle. The other is that it establishes an exotic matter sphere at the opening in order to generate a new Lorentzian wormhole within the existing one. Either way it seems to work.

Closed Wormholes
Even though a wormhole is only ever traversable between two points, there are indications that it is still connected to all the points (largely in agreement with m-theory). It is possible to pick-up energy fields in proximity of the closed end. These readings are so weak that unless the region of space has already been identified, such as when the wormhole's endpoint connects there, that they would not be discovered without a lot of research into local stellar cartography. There are some that even speculate that this might be used to send energy through a closed wormhole.

WoMD and Wormholes
There comes a time when an open wormhole is an open invitation to be invaded. The solution – wing a few nukes down the wormhole and blow it up. Unfortunately, something forged in the early universe and enduring for billions of years is not so easy to destroy. It can however be done through the timely and careful detonation of a few nukes while within the wormhole. There are so many critical parameters that simply firing a salvo into a wormhole will not work. For a start, entering a wormhole requires the negotiation of the entrance – this needing the full guidance system of a starship. There are also a lot of complicated mechanics involved in the launch – something only an officer with quite a lot of skill can achieve.
In other words it is final trip of a dedicated crew captained by an exemplary officer.
Finally, it is only a temporary solution. The maths indicate that there is also increasing resistance to sequential attempts. The first successful closure is believed to have lasted a year, but following suicide runs proved significantly less impressive. At best it is a sacrifice to buy time to meet the invasion through construction or diplomacy.

Other Wormholes There are other types of wormhole on Phoenix referred to as artificial or induced. The artificial wormhole of Dyson is similar to a Schwarzchild wormhole though the mechanics of its formation and manipulation are a well-kept secret (either that or the people responsible for its use haven't a clue and use the controls created by the Architects). Threats to open the wormhole directly on a world have so far failed to come to pass. It seems unlikely that a wormhole could be opened on a world with a stable ISR field. There is even some speculation that attempting it would cause a feedback loop capable of destroying the entire Sphere. There are induced wormholes, spontaneously created through the collapse of a gas giant that exhibits peculiar phenomena. There is debate as to whether this is not in fact a natural wormhole that is actually closed. The reason for its closure could be that subspace drift caused either the origin or one of the endpoints to align with a large gravitational well such as a giant. This would in theory cause energy and mass bleed into the wormhole each time it attempted to open, causing disruption. If a method could be determined to hold the opening open or lower local energy, the wormhole could be induced to expand, either swallowing the giant whole or destroying it utterly.