Gusty Winds in Salmon of Doubt is an incarnation of Schroedinger's Cat

Considering that it's a cat that's half alive (specifically, the front half), we don't know if the back half is still alive, and he passes a sign reading "GUSTY WINDS MAY EXIST"...

In Salmon of Doubt, a future version of Dirk is orchestrating the first few chapters.

  • The encounter with the owner of Gusty Winds would not, as he says to Kate, be possible unless someone pretty much had the information in the notebook he is carrying.
  • He called his own number and he answered.
  • The pizza place says only he has ordered that pizza.
  • The actor "lurched into sight" (presumably pushed?) just after the postman provides a memorable future reference point.
  • The handwriting on the note is "oddly familiar."
  • And, of course, the book was supposed to be about "the emergent properties of complex systems," i.e. systems that are recursive.

Professor Chronitis is a Time Lord, and his time machine is his TARDIS.

Yeah, that's right. This WMG was actually justified once. The end times are upon us.

  • Confirmed, since Shada, which featured Professor Chronitis as a Time Lord in it, is canon in the Whoniverse.
  • Bear in mind Douglas Adams did write several episodes of Doctor Who and in fact originally intended Tom Baker to be facing the Krikkitmen.

All life in the universe is a result of a stable time loop.

Life on Earth started because of an accident caused by another intelligent life form. Time travel is also possible in the Dirk Gently universe. What more evidence do you need?

Dave, from the first chapter of Salmon of Doubt, is a kangaroo.

It's mentioned that the human race is extinct, and that kangaroos are being taught to speak. Perhaps the "heavily armed kangaroos" from the description brought about the death of the human race, and now rule the world?