Theory has it that if you travel faster than the speed of light (which theory has it is impossible) then you will travel back in time.
Does this mean that if you travel faster than the speed of sound, then everything you say to a stationary observer will appear to have been said backwards?
Such as going at mach 2, saying "hello" will appear to be said "olleh"
If so, what is the science behind it?
Discuss!