Re: Matter traveling backward in time
Fri, 20 Aug 1999 11:27:16 -0700 (PDT)

Clint O'Dell [] wrote:
>Let's assume, for the moment, that there is matter that travels backward in
>time. We would never see it except for perhaps, maybe, a second. It would
>suddenly appear then suddenly disapear.

Uh, nope. I've never been too fond of this version of antimatter, but here's how it works.

  1. A particle of normal matter is moving forwards through time, minding its own business, when it's involved in a collision.
  2. That collision 'bounces' the particle back in time. It continues on, but now it's moving backwards rather than forwards, so appears like antimatter to us.
  3. The particle is involved in another collision, which bounces it forwards in time. Quite possibly it's now back on the same track as it first started, until it gets back to the first collision.

So what we see in that case is a particle interaction in which two particles are created, one of matter, and one of antimatter. After a short time, these two particles collide and annihilate, and some other particles are produced from the annihilation energy. But to the particle in question, it just appears to be going around an infinite loop, where its time direction is reversed at each collision point.