Friday, 14 March 2014
Questions About Corridors Through Time
Years ago, in "Time Travel And Poul Anderson" (on this blog and on "The Logic of Time Travel"), I made some points about Poul Anderson's time corridors that may be worth repeating.
The Length of a Corridor
A time corridor is a tube of force that is constructed in ordinary space before its length is rotated onto the temporal axis so that anyone who enters a corridor can walk or drive along it, then exit the corridor at a different time. Each corridor stretches for about six thousand years and gates into corridors overlap in time so that it is possible to travel much further into the past by exiting one corridor, traveling to another and entering it. Competing Wardens and Rangers who build and use the corridors cannot visit their future because although, whenever a new corridor is activated, its shaft stretches equally far in both directions, "'...guardians...'" (p. 36) with superior weapons bar the way to the future.
"'The conversion factor...would be roughly thirty-five days per foot'" (p. 35), or a couple of months for the width of a human body, so that there is imprecision about arrival dates. Travelers exiting a corridor must walk one behind the other holding hands in order not to arrive possibly weeks apart. My comment is that, in relativistic space-time, the conversion factor should be 186,000 miles per second so that the tube of force should stretch for six thousand light years through space before being rotated into time.
Time In The Corridor
A temporal interval outside the corridor corresponds only to a spatial interval within the corridor. Therefore, when Lockridge flees into a corridor, his pursuers, entering the corridor immediately after him, should arrive in the corridor simultaneously with him but a short distance along the corridor. Instead, they arrive at the same place in the corridor but shortly after him. Wardens or Rangers traveling along a corridor usually do not meet any other travelers along that corridor whereas surely they should meet every user of that corridor, including their past and future selves? Since the two groups are antagonistic, this would lead to an instant pitched battle within the corridor so that many Wardens or Rangers would enter it only once.
If the temporal dimension within the corridors corresponds to one of the three spatial dimensions, then it should be possible to construct a corridor in ordinary space that would give access to any moment of time within one of the time corridors. However the time in the corridors seems to be in yet another dimension:
"'Duration occurs there too, but on a different plane...'" (p. 34)
The metaphysics of the corridors is complicated and I made some further points about it in that earlier post which is a lengthy article covering Wells and Blish as well as Anderson.