“Wish granted. Electrons, being a human construct, have now always been defined slightly differently. Just as Franklin got the polarity wrong and you still use his labeling system, J.J. Thompson will now have fundamentally misunderstood the nature of the electron, leading to a cascading assumption by later scientists that the number of electrons in a neutral atom is one greater than the number of protons. Even though this completely breaks the math of quantum mechanics, everyone is just used to subtracting one at this point. This is a minutely worse world, but as a bonus, every physicist who sees you will now be preternaturally certain that you are personally to blame. You’re welcome.”