I'm pretty sure it's one of those powers the creators don't try to slip past audiences anymore. After all, who would buy it? We're not THAT confused by different time zones that we actually believe if you fly around the world in a different direction, real, actual time runs backwards.
As "new science" gets more familiar to audiences along with the understanding of how it works (or at least how it doesn't) comic creators have to abandon their old shortcuts to explaining things they didn't understand to begin with.
Think about how many older comic heroes go their powers from "radiation". It was a new and poorly understood field of science back in the 30s. Drop a couple A-bombs on Japan, and now everyone knows what happens when you irradiate a spider or a human. The spider curls up and dies, and the human has his hair fall out and throws up constantly until he dies. No spidermen or hulks coming from "radiation" anymore. Genetic Engineering (our "newer new science") became the new explanation for superheros ... even though people who actually study it know that isn't quite how it works either. For now it's still a blank cheque for superhero comic and movie writers.
Probably batman already considered this eventuality, so he create a paradox with the young bruce wayne and batman cooexist at the same time, so in this way batman can spend enterily him time to be a superheroes wiouth the discraction of the wayne company and become the greatest hero of all time, superman is just used like a source of economical energy running for the rest of him life in a huge hamster wheel.
As "new science" gets more familiar to audiences along with the understanding of how it works (or at least how it doesn't) comic creators have to abandon their old shortcuts to explaining things they didn't understand to begin with.
Think about how many older comic heroes go their powers from "radiation". It was a new and poorly understood field of science back in the 30s. Drop a couple A-bombs on Japan, and now everyone knows what happens when you irradiate a spider or a human. The spider curls up and dies, and the human has his hair fall out and throws up constantly until he dies. No spidermen or hulks coming from "radiation" anymore. Genetic Engineering (our "newer new science") became the new explanation for superheros ... even though people who actually study it know that isn't quite how it works either. For now it's still a blank cheque for superhero comic and movie writers.
Sorry for bad english, thank for attention.
Take a bow, down the curtain.
End.
XDDDDD