What theory?
We don't know of any theory in which tachyons help explain the Big
Bang, nor do we know of any evidence that there will be a Big Cruch,
with or without tachyons.
There are severe logical problems with theories in which tachyons
can interact with ordinary matter in anything like a conventional way.
The reason is that tachyons travel backwards in time in just as many
reference frames as they travel forward in time. One could then use a
string of tachyons to send meassages to ones own past, leading to all
sorts of science-fiction issues concerning causal loops- e.g whether
you could prevent your own birth.
To the best of our knowledge, the closest to a respectable use of
tachyons in a theory is the attempt of P. Pearle to construct a theory
of the non-local collapse of quantum states in the 'measurement'
process. The random nature of quantum measurement results prevents them
from carrying signals and hence avoids logical paradoxes. Such theories
are not yet very well devolped and are very hard to test.
Mike W.
(published on 10/22/2007)
