Karlos Kommented:
Thought for the day. If c represents an asymptote in the relativistic equations for time, mass, length in the direction travelled etc, assuming a particle on the brink of crossing that asymptote could pass it, the first effect of time's arrow reversing would be that it would immediately jump back the the point in time just before it crossed it....
Or something bizzare. Assuming you can get past the weirdo effects of the undefined (tends towards infinite) mass etc before you crossed that asymptote.
There's nothing random about cherenkov radiation. It's cool :-) What I can only describe as an "optical boom" :-D
Picture the following:
:-) A happy wandering little particle of normal matter is traveling north. After a while, ahead and a bit to the left, a matter/anitmatter pair of virtual particles pop into "real" existnce. Conservation of momemtun dictates that they spring into existance traveling in opposite directions to each other. As it happens, the anti-matter particle is the one traveling east, towards our earlier happy wandering particle.
Normally, the mutal attraction of such a pair of virtual particles would overcome the momentum their initial velocity, and they'd recollide, popping back out of "real" existance. However, today it not our hero's day. Because this pair of virtual interlopers popped into existance too close to our happy wanderer, the anti-matter one collides with the traveler instead.
They vanish in a burst of energy, leaving the newly formed matter particle to wander off on its own, all alone.
;-) Now ponder that perhaps what we've seen is just one particle. As it traveled, it made a turn to the east, and with the release of tremendous energy, it reversed its direction in time.
:-( Now travelling backwards in time, but still to the east, it appears to forward-time oriented people as anti-matter.
:-) After a few moments of this, it reverses direction in time agian, now traveling forward in time as the second matter particle, the one which seemed to appear out of nothing to our point of view....