It is commonly said that one can view anti-matter as 'matter going back in time'. I'm trying to figure out how far this analogy goes.
For an atom, it is well-known how that atom excites absorbing a photon, then emits a photon again.
Now assuming an anti-atom goes back in time, we would have an anti-atom, suddenly emitting a photon to become excited, then returning to normal when the photon arrives. This means the anti-atom reacts to the photon before it arrives, breaking causality.
Therefore my question is: if one where to make an anti-atom and excite it in a controlled way, would they find that the anti-atom emits before absorbing or after?
Also, if the anti-aton emits before, does that imply that the anti-atom truly has negative energy as the emitted photon contains energy and the excited state of a atom contains 'more energy of the same kind'?