Whilst possible in principle such devices remain a subject of conjecture as there are only a few accounts of archai confirming they have used such a device.
Transporting a wormhole mouth at relativistic speeds from its counterpart will result in said mouth becoming globally displaced into the future. A wormhole travelling a distance of 10 light years at 0.707c will complete the journey in ten years within its own reference frame. That reference frame is shared with the paired mouth that stayed at rest, despite an observer in the home system not observing the transported mouth arriving at its destination for 14 years. As any nexus traveller knows this phenomenon, while technically time travel, does not allow for causality violations as any traveller coming through the wormhole into the past is six years outside of their historic light cone. Thus it is impossible for any signal or vessel to arrive before they leave.
Practically speaking there is little use for this phenomenon, nor any real drawback beyond a limiting in the topology of the Nexus. Other than rare interesting examples of deep Periphery worlds joining the network with local calendars ahead of the coordinated date of the Inner Sphere there are few examples of any major positive utilisation of this arrangement. However one of these examples has been the subject of considerable interest and study for millennia: the Buy Time Machine.
BTMs are able to exploit the time displaced nature of wormholes by combining them with void mote technology (consequently BTMs are the province of archai only). Void motes, being a warped bubble of spacetime, can transport objects at seemingly ultra-high relativistic speeds. Unlike any craft attempting this using conventional methods the interior of the warp bubble experiences no time dilation. Thus a void mote travelling across ten light years at 0.99c will measure the journey time as approximately ten years, as opposed to the 1.4 years experienced by a relativistic spacecraft attempting the same journey. If this ten year journey was between two wormhole mouths separated at 0.707c according to the clock in the departure system the void mote will be seen through the wormhole to complete the journey just six years after it was observed to leave.
In theory such an arrangement can be used to "buy time". If processors inside the void mote are given a particularly computationally heavy task then by sending the mote between two time displaced wormholes extra time is gained from the reference frame of the departure system, up to 70% extra time using wormholes separated at the maximum safe velocity of 0.707c. Upon arrival the void mote can transmit its results so far back through the wormhole and, if needed, the cycle can be repeated.
The earliest known confirmation of this technique was in 5182 AT from an S1 Avatar of the lower archai Firesky; a relay node supervisor in Metasoft territory. Unlike other avatars who chose not to answer questions on BTMs (or gave delphic responses) Firesky's confirmed a few void motes had been turned into "a poor-modo's Oracle". Researchers have observed the system ever since for any interstellar void mote launches but even those confirmed to have occured cannot definitively be said to have been used for this purpose.
Exactly why a lack of confirmation exists on buy time machines is unknown. The most common theory are that they have a poor return on investment compared to making more computronium or using precious void motes for other purpose. However a popular alternative belief is that it's simply yet another aspect of archailect life that is more worth keeping away from modos than revealing. Some speculate that disasters like the Verifex catastrophe in part were the result of BTM use. Others go so far as to believe the Godweb itself is one giant poor-modo's Oracle. These fringe godwatchers devote considerable effort to tracking the movements of High Road void motes in an attempt to prove this theory. None has confirmed it in all the time they have been watching.
Text by Ryan B
Initially published on 04 July 2018.