SF Tachyons ? (Score 1)

Now What about Tachyons ? (just finnished SF Book: Timescape) Altho I belive still theorical phisichs and undetected in nature They are supposed to be faster than light and possibaly able to travel backward in time. This would seem to be an ideal communication method over very long distances (D=rt) http://en.wikipedia.org/wiki/Tachyon