Haertel And Wald

Adolph Haertel, discoverer of anti-gravity and inventor of the Haertel overdrive, appears in Welcome to Mars, which has a short sequel, "No Jokes on Mars," and in "Common Time," which is the opening story of the Galactic Cluster trilogy, and Haertel is mentioned:

in The Star Dwellers and its direct sequel, Mission To The Heart Stars, although not in its alternative sequel, "A Dusk of Idols";

in A Case Of Conscience, which is Volume III of the After Such Knowledge Trilogy;

in The Quincunx Of Time, which forms a loose trilogy with "A Style in Treason" and Midsummer Century.

Thor Wald, inventor of the Dirac transmitter and of a mathematical metalanguage, appears in The Quincunx Of Time and is mentioned in Midsummer Century.

In several timelines, Haertel succeeds Einstein. In one of those timelines, Wald, with access to many future scientific paradigms through the Dirac beep, shows that the structure of science makes it impossible to decide between the paradigms because it is one of the paradigms. However, I though that all the paradigms existed within the structure of science which is not a particular theory but a way of testing any theory?

Martian dune-cats appear in Welcome To Mars and in "No Jokes on Mars" and were referenced in a note to an early draft of "How Beautiful With Banners" although that story is set on Titan. Thus, these three works might have formed an even looser trilogy or at least a triad. Ideas proliferate. In the Haertel Scholium, Blish was not bound by a linear history but series intended as linear future histories develop their own internal inconsistencies in any case.