From Osher Doctorow

Donstockba typed:

The existence of tachyons would imply backwards time travel. Violates
cybernetics


Students and some other people who don't read arXiv and/or Front For
the Mathematics arXiv (where most of the latest research in physics,
mathematics, dynamical systems, quantitative biology is found) are
usually under your impression that the "nonexistence of tachyons" means
that they are not used in physics and astrophysics research (especially
cosmology). Type the above sites as keywords and you'll find a wealth
of papers by top researchers using tachyons but with some qualification
like "they're only virtual" or its equivalent. This is what the thread
refers to.

Also, I wouldn't counteract a physics argument with a cybernetics
argument. It's roughly like using French grammar to argue a question
in English grammar. As for backwards time travel, it's not my
obsession, but you might look up the Wheeler-Feynman or Feynman-Wheeler
absorber theory (as keywords).

Osher Doctorow