If you subscribe to the multiverse theory, there is an alternate universe where Steven Seagal played Batman in the '89 version directed by Tim Burton.

Of course, scientists are divided on the question of whether the multiverse actually exists and without some powerful trans-dimensional portals, we'll never know if it would have worked. Science has yet to catch up to the possibility of Steven Seagal playing Batman, but for now, we can only dream of that ponytail fitting into the cowl.

Speaking to Syfy Wire, 'Batman' screenwriter Sam Hamm explained the casting process for Tim Burton's movie, and how it was originally geared to action-types as opposed to Michael Keaton. "You have to make Bruce Wayne work, because Batman is, for the most part, going to be a stunt guy, or it’s going to be somebody running around in a costume in long shot," Hamm explained. "You don’t need the martial arts expertise of, say, Steven Seagal or somebody like that, because you can fake all of that kind of stuff."

As Hamm tells it, "Seagal was one of the people that was suggested to us. He had just kind of appeared on the scene, people thought holy cow, this guy’s badass. He could be Batman." Fortunately - or maybe unfortunately, who knows - Seagal never got to the point of actually reading for the role, and was quickly passed over in favour of Keaton.

What's funny, however, is that if you go back and look at 'Batman' now, you can clearly make out when it's Michael Keaton and when it's a stunt person. The advent of 4K restoration and brighter TV screens means you can see the detail in actors' faces more clearly, and it's so obvious that Keaton wasn't fighting in the alleyway scene with the swords guy.

Here's that scene, just for example's sake and because it's a great scene.