Good news! The angel Fettucini has just delivered a Message From On High: from this moment on, all politicians must be free of greed and egotism and be motivated solely by the desire for good governance and love of heir fellow man.
The, uh, bad news is that the above is true only on Earth 4072, which, of course, exists only in an alternate universe. These things are relative. To the inhabitants of Earth 4072, the news is not bad.
They can be useful, these alternate universes, especially, if you write fantasy or science fiction.
Consider Julius Schwartz, an editor at DC Comics. In 1959, he was given the task of reviving a character who had been dormant for most of the decade, the Flash. Instead of merely redoing the Flash comics readers (okay, older comics readers) were familiar with, Mr. Schwartz and his creative team gave the Flash a comprehensive makeover: new costume, new secret identity that included a new name, new origin story – the whole bag. But Mr. Schwartz had a potential problem: some of his audience – those pesky older readers – might wonder what happened to the original Flash. Mr. Schwartz provided an answer by borrowing a trope from science fiction: alternate worlds. In the Schwartz version, there were two Earths coexisting in different dimensions. The original, Jay Garrick, was on one Earth and the newer model, Barry Allen, was on the other Earth. It was the publishing equivalent of having your cake and eating it, too.
Take a bow, Mr. Schwartz.
The gimmick must have boosted sales because Mr. Schwartz soon applied it to other DC superheroes with similar success. Then other editors and their teams took the alternate Earth idea and ran with it and eventually, there were dozens of versions of Earth, each with its own pantheon of costumed heroes. This may have created story opportunities, but it also probably created confusion and narrative unwieldiness. For whatever reason, in 1985, the guys in the big offices decreed that all Earth be cosmically mashed into one, in a storyline titled Crisis on Infinite Earths that included all of DC’s superhero comics. Later, DC’s editors repeated the stunt three more times.
So…can we reach a verdict? Alternate Earths: pro or con?
Well…if you can get a good story from this, or any other, concept, yeah, sure. A good story is always its own justification. But you do risk alienating new or merely casual readers who might be confused, and you burden your inner continuity with the need to explain the multiple Earths stuff. Maybe this particular story could be told without multiple Earths elements and if that’s true, maybe it ought to be. Or do you risk compromising the uniqueness of your hero by presenting diverse versions of the character, and do you care?
You might want to mull these matters, especially if you make your living from comic books. Or you might not, but if that’s the case, why don’t you want to mull them?