Crash Course is a YouTube channel run by John and Hank Green, better known as the Vlogbrothers. The aim of the channel is to educate and inform — it started off with John teaching Crash Course World History and Hank teaching Crash Course Biology and moved on from there.
The latest class from Hank is Crash Course Philosophy and the last episode is all about the discourse of nonexistent objects and imaginary worlds, i.e. how can we talk about stuff that doesn’t exist?
The episode actually is super interesting, explaining about things like Meinong’s jungle and universes of discourse. Since imaginary worlds don’t exist, you have to assume certain things about the universe in which you are speaking. You can even use language to talk about the intersection of two different universes, such as Marvel/DC crossovers — since both universes are separate, they obey different variables. For example, in JLA/Avengers (or Avengers/JLA), Kurt Busiek wrote about how the DC Earth was slightly larger than the Marvel Earth, since it had to fit in so many more “fictional” cities, rather than use real cities like the Marvel Earth did. But then again, since the Marvel universe never had a Flash, it never had any Speed Force, therefore there was nothing for Wally West to tap into when he crossed universes.
The entire Crash Course Philosophy episodes have been super interesting, but this one is probably my favorite.