or go back in time?

You can model antiparticles as particles moving backward in time. At that level there is usually time-reversal symmetry, so the reaction looks just fine whether the clock is running forward or backward. There are some rare reactions that violate this; they all involve weak interactions.

im sorry,what i wanted to actully ask is if they in reality "go back in time".

The maths is identicle for matter going back in time and antimatter...

 

Or for that matter antimatter going back in time and normal matter...

 

Causality suggests that nothing is going back in time though.

The maths is identical for matter going back in time and antimatter.

You can model antiparticles as particles moving backward in time. There is usually time-reversal symmetry. There are some rare reactions that violate this.

 

So there are some rare cases where time-reversal symmetry doesn't apply to anti-matter and anti-matter is matter going back in time?

This means there are some rare cases where time-reversal symmetry doesn't apply to matter going back in time?

Edited September 24, 200817 yr by alan2here

So there are some rare cases where time-reversal symmetry doesn't apply to anti-matter and anti-matter is matter going back in time?

This means there are some rare cases where time-reversal symmetry doesn't apply to matter going back in time?

 

so what is it that in reality goes back in time?

Nothing.

 

Anti-particles don't "go back in time." They can, however, be described perfectly well using math exactly the same "regular" particles if you reverse the time direction.

Richard Feyman described the antiparticle mathematically as a particle moving back in time. This was taken quite literal, but it merely represents the ability to have a symetry in the equations, since symmetry is a very important factor. Such examples may involve the absorber theory which uses the idea of a time symmetry, which gave rise to the Transctional Interpretation which does involve retrocausal events.

 

So perhaps causality is broken, in very special cases. These cases however purely cannot be physical.