Fictions And Divergent Realities

What is fiction in one world might be real in another. Might human beings colonize a planet without realizing that it already has intelligent inhabitants? This is an implausible theory on Gwydion in Poul Anderson's Technic History but a reality on Nerthus in Anderson's Psychotechnic History. An author can develop the same idea in different directions.

A single fictional planet can exist in different fictional timelines. The planet, Lithia, explodes in 2050 in A Case Of Conscience by James Blish but still exists millennia later in The Seedling Stars by Blish - as do real planets like Earth and Mars, of course.

Gwydion is introduced in The Night Face and referred to as a sad case in "The Sharing of Flesh." A pyramidally structured future history series continues to incorporate new data until it reaches its apex.