Urth Net
Voyage of the Whorl: Assumptions
We now know that roughly a thousand years has passed on "the red sun whorl" since the Whorl was launched (Green's, ch 22), although only about 332 years had passed subjectively on the Whorl (Calde, ch 5).
This is a strong indication that the Whorl attained relativistic velocity during its voyage, producing a significant relativistic time dilation. It is possible, given this information and a few reasonable assumptions about the flight profile which are consistent with the text, to estimate Blue and Green's (HRTA "B&G") distance from Urth, and perhaps even guess at the identity of their sun, as well as elucidate the flight characteristics of the Whorl and its voyage.
Some observations from the text are used to formulate basic assumptions:
1. The actual trip time experienced by the Cargo seems to have been about 300 years, assuming it arrived in orbit in B&G's system about thirty years prior to the time in which BLS is set, which event apparently set off this "war of the gods" as Echidna sought to prevent the Cargo from disembarking the Whorl (Lake, ch. 11, Return, ch. 17). Interestingly enough, the Prolocutor's encyclical in Calde ch. 5 is dated the year 332! What could be referenced other than the subjective elapsed time since the voyage commenced? This fits almost too neatly.
2. The best estimate of the elapsed time back on Urth appears to be 1100 years. This is based mainly on the accepted figure for the period between the zenith of Typhon's reign to Severian's time (*1), reinforced somewhat by Horn's guesses.
Use of the data in Green's ch. 22 does indeed lead to longer elapsed Urth times, but it increases the required peak velocity even more unrealistically. Horn discounted this figure once it was arrived at, saying the rate of abandonment must have been higher at one time. The explanation is probably very simple: Typhon's "press gangs" must have depopulated entire quarters of Nessus in a relatively short period for his colonization programme.
3. Whorl is simply honkin' HUGE, having been formed of the mass of an entire sizeable asteroid (Green's ch. 25; a Neighbor stated it explicitly) hollowed by melting and centrifugal force. "Gravity" for the interior is supplied by centrifugal force. The Cargo do not seem to have noticed any significant changes in the magnitude or direction of their "gravity" throughout their remembered history, therefore all accelerations acting upon the Whorl during its voyage, for thrust, changes of direction, and the like, must be very slight by comparison with the centrifugal "gravity".
4. As a corollary to the foregoing, the Cargo do not seem to have been at all aware of when the Whorl arrived in the B&G system thirty years before the time of BLS; i.e., no inexplicable motions seem to have occurred, nor were Cargo ordered to strap themselves into crash couches or any such thing. Therefore accelerations acting on the Whorl, from the earliest memories of the original Cargo to the time of BLS, were so mild they apparently went unnoticed.
The nature of the Whorl's power plant was never explicitly divulged, but it must be tremendously powerful and provided with an astronomically vast fuel supply, even if it were antimatter. That fuel must be stored somewhere, but we're never shown precisely where. We could explore the possibility that the Whorl is a sort of low-acceleration Bussard Ramjet design, which would obviate the fuel supply problem nicely. Presumably, enough surplus fuel could be gathered by a B-R to power that fluorescent-tube-on-steroids and the other support systems on the Whorl. However, as we will see, a Bussard drive is problematical.
Larry Niven wrote extensively about B-R craft that fly between stars at a steady one gee acceleration, racking up considerable time dilation. Halfway to the destination, the craft must "turn over" and decelerate the rest of the way in order to be at approximate rest with respect to the destination. Niven's ramships' 1 gee acceleration creates gravity for the passengers (for whom "down" is toward the stern of the craft).
The Whorl cannot be accelerating at one gee for most of the trip; its "gravity" is supplied by centrifugal force, therefore it does not generate enough acceleration to be noticed by the Cargo. Doubtless it is so massive (the mass of an asteroid) that even inconceivably powerful thrusters can only nudge it along, like the engines of an oil supertanker. Furthermore, an object formed of presumably an asteroid softened and hollowed by "glass blowing" with centrifugal force, might not withstand the stress of high acceleration.
(*1) The death of Ymar, a contemporary of the end of Typhon's reign, is supposed to have been about a chiliad prior to Severian's time, per Mantis, in LU A&E #2, based on a remark made in an article in Thrust, regarding the assassin Sev found in the Second House. It follows that Typhon probably launched the Whorl roughly a century or so earlier, before the Old Sun dimmed and the Conciliator appeared. (and when did Horn ever see ruins one chiliad old before visiting Nessus? He 's seen buildings up to 300 years old, not counting the Neighbors' far older ruins that are probably more durable than those of humans).
Talarican
*This is WHORL, for discussion of Gene Wolfe's Book of the Long Sun.