# How does interpreting negative energy electrons as positrons solve the negative energy problem?

How does interpreting negative energy electrons as positive energy positrons solve the negative energy problem? How does change of “interpretation” without fixing the mathematics have such a profound impact on the underlying physics? (After all, don't we still interpret positrons and electrons as excitations of the same underlying spinor field?).

• Hi Dave - we prefer to have one question per post here, so I've removed your second one. Feel free to post it separately. – David Z Nov 18 '14 at 5:15

It basically boils down to the term $e^{-\frac i\hbar E t}$, where the minus can either be included in the energy, making it negative, or into the time. But a negative charge moving backwards in time is exactly the same as a positive charge moving forwards in time, and that is much more sensible than negative energy.